Camera module including liquid lens, optical device including the same, and method of manufacturing camera module including liquid lens

ABSTRACT

An embodiment of a camera module includes a holder configured such that the upper and lower portions of the holder are open and such that a first hole and a second hole, opposite to the first hole, are formed in the side surface of the holder, a first lens unit coupled to the upper portion of the holder, a second lens unit coupled to the lower portion of the holder, and a liquid lens disposed in the first hole and the second hole of the holder between the first lens unit and the second lens unit, the liquid lens protruding outward from the side surface of the holder, wherein at least a portion of the liquid lens may be spaced apart from the inner surface of the holder.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/366,992, filed Mar. 27, 2019; which is a continuation of U.S.application Ser. No. 15/820,119, filed Nov. 21, 2017, now U.S. Pat. No.10,281,621, issued May 7, 2019; which is a continuation of U.S.application Ser. No. 15/651,838, filed Jul. 17, 2017, now U.S. Pat. No.9,880,327, issued Jan. 30, 2018; which is a continuation ofInternational Patent Application No. PCT/KR2017/004615, filed Apr. 28,2017; which claims priority to Korean Application Nos. 10-2016-0052778,filed Apr. 29, 2016; 10-2016-0056227, filed May 9, 2016;10-2016-0114133, filed Sep. 5, 2016; and 10-2017-0013046, filed Jan. 26,2017; the disclosures of each of which are incorporated herein byreference in their entirety.

TECHNICAL FIELD

Embodiments relate to a camera module, and more particularly to a cameramodule including a liquid lens and an optical device including the same.

BACKGROUND ART

People who use portable devices demand optical devices that have highresolution, are small, and have various photographing functions (anauto-focusing (AF) function, a handshake compensation or optical imagestabilization (OIS) function, etc.). Such photographing functions may berealized by directly moving a plurality of lenses that are combined. Inthe case in which the number of lenses is increased, however, the sizeof the optical devices may be increased.

The auto-focusing and handshake compensation functions are performed bytilting or moving a lens module including a plurality of lenses, whichis fixed to a lens holder in the state in which the optical axes of thelens are aligned, along the optical axis or in the directionperpendicular to the optical axis. An additional lens moving apparatusis used to move the lens module.

However, the lens moving apparatus has high power consumption, drivingmembers, such as a magnet and a coil, are required to move the lensmodule, and available space for moving the lens module is needed inamount corresponding to the range in which the lens module is to bemoved. As a result, the thickness of a camera module and an opticaldevice is increased.

Therefore, research has been conducted on a liquid lens configured suchthat the curvature of the interface between two kinds of liquids iselectrically adjusted to perform the auto-focusing and handshakecompensation functions.

DISCLOSURE Technical Problem

Embodiments provide a lens having a simple structure and a camera moduleincluding the same.

In addition, embodiments provide a lens assembly having a miniaturizedstructure and a camera module including the same.

In addition, embodiments provide a lens module configured such that aliquid lens is located in the middle of the lens module so as to reducethe size of the module and such that lenses are simultaneously alignedusing a single core and a method of manufacturing the lens module.

In addition, embodiments provide a liquid lens configured such that whenlenses are inserted, the physical interference between neighboringlenses is minimized and a lens module including the same.

In addition, embodiments provide a camera module and an optical deviceincluding a liquid lens and a lens module.

In addition, embodiments provide a camera module and an optical deviceincluding a liquid lens, wherein the liquid lens is stably disposed in alens assembly.

In addition, embodiments provide a camera module and an optical deviceincluding a liquid lens, wherein the performance of optical lenses otherthan the liquid lens is easily evaluated.

It should be noted that the objects of the disclosure are not limited tothe objects mentioned above, and other unmentioned objects of thedisclosure will be clearly understood by those skilled in the art towhich the disclosure pertains from the following description.

Technical Solution

An embodiment of a lens may include a core having therein a hollow, anelectrode layer disposed on the core, an upper glass coupled to theupper side of the core, a lower glass coupled to the lower side of thecore, and a liquid lens unit disposed in the hollow in the core, whereinthe electrode layer may be disposed on the upper surface and the lowersurface of the core, and the lens may include a through-hole forconnecting the electrode layer disposed on the upper surface of the coreand the electrode layer disposed on the lower surface of the core toeach other.

The electrode layer may extend to the hollow in the core.

The core may include a pattern unit having a plurality of terminals.

The liquid lens unit may include a first liquid layer, which is made ofa conductive liquid and is connected to the electrode layer, and asecond liquid layer, which is made of a nonconductive liquid and isdisposed so as to abut the first liquid layer.

An embodiment of a lens may further include an insulation layer disposedbetween the electrode layer and the second liquid layer.

The electrode layer may be deposited on the upper surface and the lowersurface of the core, the surface of the hollow, and the surface of thethrough-hole.

The pattern unit may be formed on the deposited electrode layer.

The pattern unit may be configured such that terminals are separatedfrom each other, and at least one of the terminals may be connected tothe electrode layer deposited on the upper surface of the core and thethrough-hole.

The pattern unit may include a first pattern unit coupled to the lowerglass and a second pattern unit exposed from the lower glass.

The second pattern unit may be configured to be exposed at one side ofthe lower glass.

The second pattern unit may be an external printed circuit board.

Each of the terminals may include the electrode layer formed on theupper surface of the core and a first terminal connected to theelectrode layer formed in the through-hole.

An embodiment of a lens may include a core on which an electrode layeris disposed, an upper glass coupled to the upper side of the core, alower glass coupled to the lower side of the core, a liquid lens unitdisposed in a hollow formed in the core, and an insulation layerdisposed between the electrode layer and the liquid lens unit, whereinthe core may include a through-hole, on the surface of which theelectrode layer is disposed, connected to the electrode layer disposedon the upper surface of the core, and a pattern unit formed on the lowersurface of the core, the pattern unit being configured such thatterminals are separated from each other.

An embodiment of a camera module may include the lens and an imagesensor provided so as to be opposite to the lens in the optical-axisdirection.

An embodiment of a lens assembly may include a base having therein athrough-hole, a first lens unit disposed in the through-hole, a secondlens unit disposed in the through-hole so as to be spaced apart from thefirst lens unit, and a liquid lens unit disposed between the first lensunit and the second lens unit, wherein the base may include an insertionhole, through which the liquid lens unit is inserted.

An embodiment of a lens assembly may further include a printed circuitboard connected to the liquid lens unit, at least a portion of theprinted circuit board being inserted through the insertion hole.

An embodiment of a lens assembly may further include a cover member forreceiving the base and the printed circuit board.

The first lens unit may include an exposure lens exposed outside thebase, and the exposure lens may be made of a glass material.

The exposure lens may have a diamond like carbon (DLC) coating layerformed on the exposed portion thereof.

The first lens unit, the second lens unit, and the liquid lens unit maybe disposed so as to be opposite to each other in the optical-axisdirection

The liquid lens unit may be provided with a hollow, which is filled withliquid and through which the light that has passed through the firstlens unit is transmitted.

The area of the hollow in the optical-axis direction may be less thanthe area of the lens constituting the first lens unit or the second lensunit in the optical-axis direction.

The area of the hollow in the optical-axis direction may graduallydecrease from the first lens unit to the second lens unit.

Another embodiment of a lens assembly may include a first lens unitdisposed at the front thereof, a second lens unit disposed at the rearof the first lens unit, a liquid lens unit disposed between the firstlens unit and the second lens unit, a base, in which the first lensunit, the second lens unit 1200, and the liquid lens unit are mounted,the base being provided in the edge thereof with an insertion hole,through which the liquid lens unit is inserted, a printed circuit boardconnected to the liquid lens unit, one end of the printed circuit boardbeing inserted through the insertion hole, and a cover member forreceiving the base and the printed circuit board, wherein the first lensunit may include an exposure lens exposed outside the base, and at leasta portion of the exposure lens may be made of a glass material.

An embodiment of a camera module may include the lens assembly and animage sensor provided so as to be opposite to the lens assembly in theoptical-axis direction.

An embodiment of a liquid lens may include a core plate having therein acavity for receiving a conductive liquid and a nonconductive liquid, anelectrode unit coated on the surface of the core plate, an insulationunit coated on the electrode unit along the inner surface of the cavity,an upper plate coupled to the core plate at the upper side of the coreplate, the upper plate having at least one recess, through which aportion of the upper surface of the core plate is exposed, a lower platecoupled to the core plate at the lower side of the core plate, the lowerplate having at least one recess, through which a portion of the lowersurface of the core plate is exposed, an upper board located at theupper side of the upper plate, and a lower board located at the lowerside of the lower plate, wherein the upper board and the electrode unitmay be connected to each other via an upper conductive portion disposedin the recess formed in the upper plate, and the lower board and theelectrode unit may be connected to each other via a lower conductiveportion disposed in the recess formed in the lower plate.

The recesses formed in the upper plate and the recesses formed in thelower plate may be formed at positions corresponding to the corners ofthe core plate.

The recesses formed in the upper plate may be formed in the sides of theupper plate, and the recesses formed in the lower plate may be formed inthe sides of the lower plate.

The corners of the upper board and the lower board may be locatedfurther inward than the corners of the core plate.

The sides of the upper board and the lower board may be located furtherinward than the sides of the core plate.

The number of recesses formed in the upper plate may be four, and thenumber of recesses formed in the lower plate may be four.

The recesses may be holes.

The recesses formed in the upper plate may be holes formed through theupper plate, and the recesses formed in the lower plate may be holesformed through the lower plate.

The upper board may be provided at the portion thereof corresponding tothe cavity with an upper guide hole extending to one side.

An embodiment of a camera module may include a lens holder having a holeformed therethrough in the upward-downward direction, a liquid lensreceived in the hole, a first lens unit received in the hole, the firstlens unit being disposed on the liquid lens, a second lens unit receivedin the hole, the second lens unit being disposed under the liquid lens,and an insertion hole formed through a portion of the side surface ofthe lens holder such that the liquid lens is inserted through theinsertion hole, wherein the liquid lens may include a core plate havingtherein a cavity for receiving a conductive liquid and a nonconductiveliquid, an electrode unit coated on the surface of the core plate, aninsulation unit coated on the electrode unit along the inner surface ofthe cavity, an upper plate coupled to the core plate at the upper sideof the core plate, the upper plate having at least one recess, throughwhich a portion of the upper surface of the core plate is exposed, alower plate coupled to the core plate at the lower side of the coreplate, the lower plate having at least one recess, through which aportion of the lower surface of the core plate is exposed, an upperboard located at the upper side of the upper plate, and a lower boardlocated at the lower side of the lower plate, and wherein the upperboard and the electrode unit may be connected to each other via an upperconductive portion disposed in the recess formed in the upper plate, andthe lower board and the electrode unit may be connected to each othervia a lower conductive portion disposed in the recess formed in thelower plate.

The insertion hole may be formed in the direction perpendicular to theoptical-axis direction.

The upper board may be provided at the portion thereof corresponding tothe first lens unit with an upper guide hole extending to one side.

An inclined portion may be located along the outer circumference of thelower surface of the lowermost lens of the first lens unit.

The inclined portion may be formed so as to be inwardly inclineddownward.

An embodiment of a method of manufacturing a lens module may include afirst step of molding a lens holder having a hole formed in theoptical-axis direction and an insertion hole formed by opening a portionof the side surface thereof in the direction perpendicular to theoptical axis, a second step of inserting a first lens unit into theupper side of the hole in the optical-axis direction, a third step ofinserting a liquid lens through the insertion hole such that the liquidlens is located at the lower side of the first lens unit in the hole,and a fourth step of inserting a second lens unit into the lower side ofthe hole in the optical-axis direction.

An embodiment of a camera module may include a lens holder having a holeformed therethrough in the upward-downward direction, a liquid lensreceived in the hole, a first lens unit received in the hole, the firstlens unit being disposed on the liquid lens, a second lens unit receivedin the hole, the second lens unit being disposed under the liquid lens,and a main board having an image sensor mounted thereon, the lens holderhaving an insertion hole formed by opening a portion of the side surfacethereof such that the liquid lens is inserted through the insertionhole, wherein the liquid lens may include a core plate having therein acavity for receiving a conductive liquid and a nonconductive liquid, anelectrode unit coated on the surface of the core plate, an insulationunit coated on the electrode unit along the inner surface of the cavity,an upper plate coupled to the core plate at the upper side of the coreplate, the upper plate having at least one recess, through which aportion of the upper surface of the core plate is exposed, a lower platecoupled to the core plate at the lower side of the core plate, the lowerplate having at least one recess, through which a portion of the lowersurface of the core plate is exposed, an upper board located at theupper side of the upper plate, and a lower board located at the lowerside of the lower plate, and wherein the upper board and the electrodeunit may be connected to each other via an upper conductive portiondisposed in the recess formed in the upper plate, and the lower boardand the electrode unit may be connected to each other via a lowerconductive portion disposed in the recess formed in the lower plate.

The liquid lens may further include an upper connection board forconnecting the upper board to the main board and a lower connectionboard for connecting the lower board to the main board.

The liquid lens may further include an upper and lower connection boardfor connecting the upper board and the lower board to each other and alower connection board for connecting the lower board to the main board.

An embodiment may provide a camera module including a holder configuredsuch that the upper and lower portions of the holder are open and suchthat a first hole and a second hole, opposite to the first hole, areformed in the side surface of the holder, a first lens unit coupled tothe upper portion of the holder, a second lens unit coupled to the lowerportion of the holder, and a liquid lens disposed in the first hole andthe second hole of the holder between the first lens unit and the secondlens unit, the liquid lens protruding outward from the side surface ofthe holder, wherein at least a portion of the liquid lens may be spacedapart from the inner surface of the holder.

The holder may be provided therein with a through-hole for connectingthe first hole and the second hole to each other, and the through-holemay be provided therein with a first region, in which the first lensunit is disposed, a second region, in which the liquid lens is disposed,and a third region, in which the second lens unit is disposed.

The camera module may further include a cover for covering a portion ofthe side surface of the holder and a portion of the upper surface of theholder, wherein the cover may cover the first hole and the second hole.

The horizontal length of the second region may be greater than thehorizontal length of the first region and the horizontal length of thethird region.

The liquid lens may include a first plate having therein a cavity forreceiving a first conductive liquid and a second nonconductive liquid, afirst electrode disposed on the first plate, a second electrode disposedunder the first plate, a second plate disposed on the first electrode,and a third plate disposed under the second electrode.

The second plate and the third plate may be bonded to the holder usingepoxy.

At least one of the second plate and the third plate may be spaced apartfrom the inner surface of the holder.

The horizontal length of the first lens unit in the region adjacent tothe liquid lens may be greater than the horizontal length of the cavityin the region adjacent to the first lens unit.

The horizontal length of the second lens unit in the region adjacent tothe liquid lens may be greater than the horizontal length of the cavityin the region adjacent to the second lens unit.

The first lens unit may include a plurality of lenses, and the holdermay have a stair structure at the inner wall of the first region,wherein the edges of the lenses contact the stair structure.

The second lens unit may include a plurality of lenses, and the holdermay have a stair structure at the inner wall of the third region,wherein the edges of the lenses contact the stair structure.

Another embodiment may provide an optical device including a cameramodule including a holder configured such that the upper and lowerportions of the holder are open and such that a first hole and a secondhole, opposite to the first hole, are formed in the side surface of theholder, a first lens unit coupled to the upper portion of the holder, asecond lens unit coupled to the lower portion of the holder, and aliquid lens disposed in the first hole and the second hole of the holderbetween the first lens unit and the second lens unit, the liquid lensprotruding outward from the side surface of the holder, wherein at leasta portion of the liquid lens is spaced apart from the inner surface ofthe holder, a controller for converting an image incident through thecamera module into an electrical signal, and a display module comprisinga plurality of pixels, the colors of which are changed by the electricalsignal.

A further embodiment may provide a method of manufacturing a lens moduleincluding a liquid lens, the method including a first step of preparinga holder configured such that the upper and lower portions of the holderare open and such that a first hole and a second hole, opposite to thefirst hole, are formed in the side surface of the holder, a second stepof coupling a first lens unit to the upper portion of the holder, athird step of coupling a second lens unit to the lower portion of theholder, and a fourth step of inserting a liquid lens into a gap betweenthe first lens unit and the second lens unit, wherein the liquid lensmay protrude further outward than the side surface of the holder.

The method may further include a step of supporting the side surface ofthe liquid lens disposed so as to protrude further outward than the sidesurface of the holder to adjust the position of the liquid lens and astep of bonding the liquid lens to the holder.

Advantageous Effects

In embodiments, the deposition layer formed on the upper surface and thelower surface of the core may be connected to an external power supplyvia the pattern unit formed on the lower surface of the core.Consequently, the lens may have a structure that is simpler than thestructure in which the deposition layer formed on the upper surface andthe lower surface of the core is connected to the external power supply.

In addition, since the lens has a simple structure, the structure of thelens and the camera module including the same may be simplified andminiaturized. As a result, the time, effort, and cost required tomanufacture the lens and the camera module including the same may bereduced.

In addition, the use of an additional cover glass to protect the exposedportion of the lens assembly, i.e. the exposure lens, may be obviated.Consequently, the size of a space in which the lens assembly and thecamera module including the same are mounted may be reduced, with theresult that the size of a device in which the lens assembly and thecamera module are mounted may be effectively reduced.

In addition, the liquid lens unit may be mounted in the base through theinsertion hole, whereby the lens assembly may be easily assembled.

In addition, the focus of the liquid lens unit mounted in the basethrough the insertion hole may be easily aligned with the focus of thefirst lens unit in the optical-axis direction.

In addition, the lenses of the lens module may be aligned using a singlecore, whereby optical-axis twisting or optical-axis deviation may beinhibited.

In addition, the liquid lens may be inserted into the middle of the lensmodule, whereby the lens module may have a compact structure.

In addition, no friction may occur between neighboring lenses when theliquid lens is inserted, whereby wear of the liquid lens may beinhibited. As a result, the defect rate of the lens module may bereduced.

In addition, in the camera module including the liquid lens according tothe embodiment, the interface between the first and second liquids maybe changed using electricity, whereby the size of the camera device maybe reduced. Furthermore, AF or OIS may be performed using electricity,whereby power consumption may be reduced and the size of the cameradevice may be smaller than in the case in which the lenses aremechanically moved.

In addition, the liquid lens may be inserted into the holder, wherebythe liquid lens may be stably disposed.

In addition, the liquid lens may be inserted after the opticalperformance of the first and second lens units is evaluated in the statein which the first lens unit and the second lens unit are disposed inthe holder.

DESCRIPTION OF DRAWINGS

FIG. 1 is an exploded perspective view showing a lens according to anembodiment;

FIG. 2 is a perspective view showing the lens according to theembodiment;

FIG. 3 is a side view showing the lens according to the embodiment;

FIG. 4 is a schematic sectional view illustrating the structure of FIG.3;

FIG. 5 is a plan view showing a lens according to an embodiment;

FIG. 6 is a bottom view showing the lens according to the embodiment;

FIGS. 7 and 8 are views illustrating a coupling structure between thelens according to the embodiment and an external printed circuit;

FIG. 9 is a side sectional view showing a lens assembly according to anembodiment;

FIG. 10 is an exploded perspective view of FIG. 9;

FIG. 11 is a perspective view showing a camera module according to anembodiment;

FIG. 12 is a view showing the internal structure of FIG. 11;

FIG. 13 is a perspective view showing a camera module provided with acover member according to another embodiment;

FIG. 14 is a view showing the state in which the camera module of FIG.13 is mounted in a device;

FIG. 15 is a conceptual view showing an electrowetting phenomenon;

FIG. 16 is a perspective view showing a camera module according to afirst embodiment;

FIG. 17 is an exploded perspective view showing the camera moduleaccording to the first embodiment;

FIG. 18 is a perspective view showing a shield can according to a firstembodiment;

FIG. 19 is a perspective view showing a lens holder according to a firstembodiment;

FIG. 20 is a sectional view showing the lens holder according to thefirst embodiment;

FIG. 21 is an exploded perspective view showing a liquid lens accordingto a first embodiment;

FIG. 22 is a plan view showing the liquid lens according to the firstembodiment;

FIGS. 23A through 23L are conceptual sectional views showing that aconductive liquid and a nonconductive liquid are received in a cavity infirst and second embodiments;

FIG. 24 is a sectional view showing the camera module according to thefirst embodiment;

FIG. 25 is an exploded perspective view showing a camera moduleaccording to a second embodiment;

FIG. 26 is an exploded perspective view showing a liquid lens accordingto a second embodiment;

FIG. 27 is a sectional view showing the camera module according to thesecond embodiment;

FIG. 28 is a conceptual view showing a method of manufacturing the lensmodule according to the first embodiment;

FIG. 29 is a conceptual view showing a method of manufacturing the lensmodule according to the second embodiment;

FIG. 30 is a flowchart showing the method of manufacturing the lensmodule according to the first or second embodiment;

FIG. 31 is a view showing an embodiment of the camera module;

FIGS. 32A and 32B are views showing a liquid lens of the camera moduleof FIG. 31;

FIGS. 33 and 34 are sectional views showing a lens assembly of thecamera module of FIG. 31; and

FIG. 35 is a view showing the structure of the lens assembly of thecamera module of FIGS. 33 and 34, from which the liquid lens is removed.

FIGS. 36A and 36B are perspective views from a first direction and asecond direction, respectively, of the holder of the camera module shownin FIG. 31.

BEST MODE

A camera module according to an embodiment may include a holderincluding a first side surface having a first hole and a second sidesurface having a second hole facing the first hole, a first lens unitdisposed in the holder, a second lens unit disposed in the holder, and aliquid lens disposed between the first lens unit and the second lensunit, at least a portion of the liquid lens being disposed in the firsthole and the second hole in the holder, wherein the thickness of theliquid lens may be less than the size of the first hole in the holder inthe optical-axis direction.

MODE FOR INVENTION

Reference will now be made in detail to the preferred embodiments,examples of which are illustrated in the accompanying drawings. Whilethe disclosure is susceptible to various modifications and alternativeforms, specific embodiments thereof are shown by way of example in thedrawings. However, the disclosure should not be construed as limited tothe embodiments set forth herein, but on the contrary, the disclosure isto cover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the embodiments.

It may be understood that, although the terms “first,” “second,” etc.may be used herein to describe various elements, these elements are notto be limited by these terms. These terms are generally only used todistinguish one element from another. In addition, terms particularlydefined in consideration of the construction and operation of theembodiments are used only to describe the embodiments, but do not definethe scope of the embodiments.

In the following description of the embodiments, it will be understoodthat, when each element is referred to as being “on” or “under” anotherelement, it can be “directly” on or under another element or can be“indirectly” formed such that an intervening element is also present. Inaddition, when an element is referred to as being “on” or “under,”“under the element” as well as “on the element” may be included based onthe element.

In addition, relational terms, such as “on/upper part/above” and“under/lower part/below,” are used only to distinguish between onesubject or element and another subject or element without necessarilyrequiring or involving any physical or logical relationship or sequencebetween such subjects or elements.

The term “optical-axis direction” used herein is defined as theoptical-axis direction of a lens module of a camera module. Meanwhile,the “optical-axis direction” may also be referred to as anupward-downward direction or a z-axis direction.

The term “auto focus” used herein is defined as a function of changingthe curvature of the interface of a liquid lens to focus a subject.Herein, the term “auto focus” may be used interchangeably with “AF.”

The term “handshake compensation” used herein is defined as a functionof changing the curvature of the interface of the liquid lens to offsetthe vibration (the movement) of an image sensor due to external force.Herein, the term “handshake compensation” may be used interchangeablywith “optical image stabilization (OIS).”

FIG. 1 is an exploded perspective view showing a lens according to anembodiment. FIG. 2 is a perspective view showing the lens according tothe embodiment. The lens according to the embodiment may include a core100, an upper glass 200, a lower glass 300, a liquid lens unit 400, anda insulation layer 500.

The upper glass 200 may be coupled to the upper side of the core 100 toprotect the core 100. In addition, the upper glass 200 may inhibit theleakage of the liquid from the liquid lens unit 400, provided in thecore 100.

The lower glass 300 may be coupled to the lower side of the core 100 toprotect the core 100. In addition, the lower glass 300 may inhibit theleakage of the liquid from the liquid lens unit 400, provided in thecore 100, together with the upper glass 200.

The upper glass 200 and the lower glass 300 may be made of a transparentsolid material. For example, the upper glass 200 and the lower glass 300may be made of a transparent glass or plastic material. Light may beincident on the upper glass 200, may pass through the core 100 and thelower glass 300, and may be incident on an image sensor (not shown). Inaddition, light may be incident on the lower glass 300, may pass throughthe core 100 and the upper glass 200, and may be incident on the imagesensor (not shown).

At least some of the liquid in the liquid lens unit 400 may be providedin a hollow 120 formed in the core 100 in the optical-axis direction.For example, the liquid may include a plurality of liquids that are notmixed with each other. The shape or curvature of the interface betweenthe respective liquids may be changed such that a camera moduleincluding the lens performs auto focusing and handshake compensation.The structure of the liquid lens will be described below in detail withreference to the drawings.

The core 100 may be disposed between the upper glass 200 and the lowerglass 300, and may include an electrode layer 110, a hollow 120,through-holes 130, and a pattern unit 140.

The electrode layer 110 may be disposed on the core 100, may bedeposited on the core 100 in the shape of a thin film, and may be madeof a conductive material. The electrode layer 110 may be disposed on thecore 100 using chemical vapor deposition, plasma vacuum deposition, orother methods.

The hollow 120 may formed through the core 100. The liquid lens unit 400may be provided in at least a portion of the hollow 120. The hollow 120is a region of the core 100 through which light passes after havingpassed through the upper glass 200 or the lower glass 300. At least aportion of the electrode layer 110 may extend to the hollow 120 in thecore 110.

The through-holes 130 may be formed through the core 100, and anelectrode layer 110 connected to the electrode layer 110 deposited onthe upper surface of the core 100 may extend through the through-holes130. The deposited layer may be deposited on the surfaces of thethrough-holes 130 so as to be connected to the electrode layer 110 onthe upper surface of the core 100.

The pattern unit 140 may be formed on the lower surface of the core 100,and may have a plurality of terminals 143. The structure of the patternunit 140 will be described below in detail with reference to thedrawings.

FIG. 3 is a side view showing the lens according to the embodiment. FIG.4 is a schematic sectional view illustrating the structure of FIG. 3.

As shown in FIG. 4, the electrode layer 110 may be disposed on the uppersurface and the lower surface of the core 100, the surface of the hollow120, and the surfaces of the through-holes 130 by deposition.

In this structure, the deposition layers formed on the upper surface andthe lower surface of the core 100 may be connected to each other via thedeposition layer formed on the surfaces of the through-holes 130. Thatis, the electrode layers 110 disposed on the upper surface and the lowersurface of the core 100 may be connected to each other via thethrough-holes 130.

As shown in FIG. 4, the liquid lens unit 400 may include a first liquidlayer 410 and a second liquid layer 420. The first liquid layer 410 maybe made of a conductive liquid, and may be connected to the electrodelayer 110. The second liquid layer 420 may be made of a nonconductiveliquid, and may be disposed so as to abut the first liquid layer 410.The hollow 120 may be filled with at least a portion of the first liquidlayer 410 and the second liquid layer 420.

In addition, the first liquid layer 410 and the second liquid layer 420may abut each other in the state of not being mixed with each other. Thefirst liquid layer 410 may be connected to the electrode layer 110 toreceive current from an external power supply via the electrode layer110.

When voltage is applied to the first liquid layer 410 or when current issupplied to the first liquid layer 410, the shape or curvature of theinterface between the first liquid layer 410 and the second liquid layer420 may be changed. Consequently, the shape or curvature of theinterface between the first liquid layer 410 and the second liquid layer420 may be adjusted by controlling the voltage applied to the firstliquid layer 410 or the current supplied to the first liquid layer 410,whereby the camera module including the lens according to the embodimentmay perform auto focusing and handshake compensation.

The insulation layer 500 may be disposed between the electrode layer 110and the second liquid layer 420. Specifically, as shown in FIG. 4, theinsulation layer 500 may be formed on a portion of the upper surface ofthe core 100, the surface of the hollow 120, and a portion of the uppersurface of the lower glass 300. The insulation layer 500 may be stackedon the surface of the electrode layer 110 in the upper surface of thecore 100 and the surface of the hollow 120.

The insulation layer 500 may inhibit the first liquid layer 410, made ofa conductive material, from coming into direct contact with theelectrode layer 110 formed on the lower surface of the core 100. To thisend, the insulation layer 500 may be stacked on the entirety of theregion in which the first liquid layer 410 may directly contact theelectrode layer 110 on the lower surface of the core 100, as describedabove.

As the insulation layer 500 is disposed as described above, the firstliquid layer 410 may be connected to the electrode layer 110 on thelower surface of the core 100 through the through-holes 130.

Meanwhile, the core 100 of the embodiment shown in FIG. 4 may be formedthrough the following processes.

First, a hollow 120 and through-holes 130 are formed in the core 100.Subsequently, an electrode layer 110 is deposited on the upper surfaceand the lower surface of the core 100, the surface of the hollow 120,and the surfaces of the through-holes 130. As will be described below, apattern unit 140 may be formed on the electrode layer 110 deposited onthe lower surface of the core 100.

Subsequently, a lower glass 200 is coupled to the lower surface of thecore 100 by fusion. Subsequently, an insulation layer is stacked on thecore 100.

Subsequently, liquid is poured into the core 100 to form a liquid lensunit 400 including a first liquid layer 410 and a second liquid layer420. Finally, an upper glass 200 is coupled to the upper surface of thecore 100 by fusion, whereby the core 100 is assembled.

Voltage is applied to the lens or current is supplied to the lens inorder to operate the lens. In the case in which the electrode layer 110on the upper surface of the core 100 and the electrode layer 110 on thelower surface of the core 100 are not connected to each other,additional connectors for connection with the external power supply maybe connected to the electrode layers 110 on the upper surface and thelower surface of the core 100.

In the structure in which such additional connectors are connected,however, the structure of the lens and the camera module including thesame is complicated and has a large size. As a result, the time, effort,and cost required to manufacture the lens and the camera moduleincluding the same are increased. Hereinafter, the structure of anembodiment that is capable of solving the above problem will bedescribed in detail.

FIG. 5 is a plan view showing a lens according to an embodiment (see thesolid line of the figure). FIG. 6 is a bottom view showing the lensaccording to the embodiment. As shown in FIGS. 5 and 6, thethrough-holes 130, having the electrode layer 110 formed on the surfacesthereof, may connect the electrode layer 110 on the upper surface of thecore 100 and the pattern unit 140 on the lower surface of the core 100to each other.

The sectional view of FIG. 4 may correspond to a sectional view takenalong line A-A′ of FIG. 6.

The pattern unit 140 may be formed on the deposited electrode layer 110.That is, the electrode layer 110 deposited on the lower surface of thecore 100 may be patterned by etching to form the pattern unit 140.

As shown in FIG. 6, the pattern unit 140 may be configured such thatterminals 143 are separated from each other, and at least one of theterminals 143 may be connected to the electrode layer 110 deposited onthe upper surface of the core 100 and the through-holes 130.

In this structure, the terminals 143 may be connected to the electrodelayers 110 on both the upper surface and the lower surface of the core100. In addition, according to this embodiment, at least some of theterminals 143 may be connected to the first liquid layer 410 via theelectrode layer 110 on the upper surface of the core 100.

As shown in FIG. 6, the pattern unit 140 may include a first patternunit 141 and a second pattern unit 142. The first pattern unit 141 is aregion that is coupled to the lower glass 300, and the second patternunit 142 is a region that is exposed at one side of the lower glass 300.

The second pattern unit 142 may be connected to an external printedcircuit board 10. Consequently, the second pattern unit 142 may bespaced apart from the external printed circuit board 10 by apredetermined distance so as to be easily connected to the externalprinted circuit board 10, and may be constituted by portions of theterminals 143 having the same or similar shapes.

Meanwhile, the terminals 143 may include first terminals 143 a. As shownin FIG. 6, for example, the first terminals 143 a may be connected tothe electrode layer 110 formed on the upper surface of the core 100 andthe electrode layer 110 formed in the through-holes 130.

The electrode layer 110 on the upper surface of the core 100 may bedisposed on the upper surface of the core 100 about the hollow 120 in acircular shape. The electrode layer 110 on the upper surface of the core100 may be connected to the first terminals 143 a via the electrodelayer 110 formed in the through-holes 130 so as to receive the samecurrent from the external power supply. The electrode layer 110connected to the first terminals 143 a may be defined as a commonelectrode.

The other terminals 143 excluding the first terminals 143 a may beconnected to the electrode layers 110 that divide the circumference ofthe hollow 120 into four regions in the pattern unit 140 on the lowersurface of the core 100. The electrode layers 110 corresponding to thefour regions may be disposed under the insulation layer 500 along theinclined surface of the hollow 120. The electrode layers 110corresponding to the four regions may receive current through the otherterminals 143, excluding the first terminals 143 a. The electrode layers110 connected to the other terminals 143 excluding the first terminals143 a may be defined as individual electrodes. When current is suppliedfrom the external power supply via the terminals 143 including the firstterminals 143 a, therefore, the shape or curvature of the interfacebetween the first liquid layer 410 and the second liquid layer 420 maybe changed.

Consequently, the camera module including the lens may perform autofocusing and handshake compensation.

FIGS. 7 and 8 are views illustrating a coupling structure between thelens according to the embodiment and an external printed circuit.

As shown in FIGS. 7 and 8, the terminals 143 of the pattern unit 140 maybe connected to the external printed circuit board 10 in the secondpattern unit 142, which is exposed at one side of the lower glass 300.

The external printed circuit board 10 may be provided on both endsthereof with external terminals 11. One of the external terminals 11 maybe connected to the lens, and the other may be connected to the externalpower supply.

In the second pattern unit 142 of the lens, the terminals 143 may becoupled to the external terminals 11 of the external printed circuitboard 10. The terminals 143 may be coupled and connected to the externalterminals 11 by soldering or fusion or using a conductive film or anadhesive.

In the embodiment, the deposition layer formed on the upper surface andthe lower surface of the core 100 may be connected to the external powersupply only in the pattern unit 140 formed on the lower surface of thecore 100. Consequently, the above structure is simpler than thestructure in which the deposition layer on the upper surface and thelower surface of the core 100 is connected to the external power supply.

Since the lens has a simple structure, as described above, the structureof the lens and the camera module including the same may be simplifiedand miniaturized. As a result, the time, effort, and cost required tomanufacture the lens and the camera module including the same may bereduced.

The camera module including the lens may further include an image sensor(not shown). The image sensor may be provided so as to be opposite tothe lens in the optical-axis direction.

Consequently, light may be incident on the image sensor after passingthrough the lens, and images of a subject may be formed on the imagesensor.

Meanwhile, an infrared cutoff filter may be provided between the lensand the image sensor so as to be opposite to the lens and the imagesensor in the optical-axis direction. The infrared cutoff filter mayimprove the quality of images formed on the image sensor.

The core 100, the electrode layer 110 on the upper surface of the core100, the electrode layer 110 on the lower surface of the core 100, thehollow 120, the upper glass 200, the lower glass 300, described withreference to FIGS. 1 to 6, may also be defined as a first plate, a firstelectrode, a second electrode, a cavity, a second plate, and a thirdplate, respectively.

FIG. 9 is a side sectional view showing a lens assembly according to anembodiment. The lens assembly according to the embodiment may include afirst lens unit 1100, a second lens unit 1200, a liquid lens unit 1300,a base 1400, a printed circuit board 1500, and a cover member 1600.

The first lens unit 1100 is a front part of the lens assembly, on whichlight is incident from outside the lens assembly. The first lens unit1100 may be constituted by at least one lens. Alternatively, two or morelenses may be aligned in the optical-axis direction to constitute anoptical system.

The first lens unit 1100 may be mounted in the base 1400. A through-holemay be formed in the base 1400, and the first lens unit 1100 may bedisposed in the through-hole.

The first lens unit 1100 may include an exposure lens 1110. The exposurelens 1110 is a lens that protrudes out of the base 1400 so as to beexposed to the outside. Since the exposure lens 1110 is exposed to theoutside, the surface of the lens may be easily damaged.

In the case in which the surface of the lens is damaged, the quality ofimages taken by the camera module may be deteriorated. Consequently, itis necessary to inhibit or restrain damage to the surface of theexposure lens 1110.

In order to inhibit damage to the surface of the exposure lens 1110, acover glass may be disposed in front of the exposure lens 1110. In thecase in which the cover glass is disposed, however, the size of thespace in which the lens assembly and the camera module including thesame are mounted may be increased, with the result that the size of adevice in which the lens assembly and the camera module including thesame are mounted may be increased.

In the embodiment, therefore, a structure for inhibiting or restrainingdamage to the surface of the exposure lens 1110 without using the coverglass is provided by way of example.

In the embodiment, at least a portion of the exposure lens 1110 may bemade of a wear-resistant material, such as a glass material, in order toinhibit or restrain damage to the surface of the exposure lens 1110.

For example, the entirety of the exposure lens 1110 may be made of aglass material, which exhibits high wear resistance. In the case inwhich the exposure lens 1110 is made of a glass material, which exhibitshigh wear resistance, damage to the surface of the exposure lens 1110 ismore effectively inhibited or restrained than in the case in which theexposure lens 1110 is made of a plastic material.

In another embodiment, the exposure lens 1110 may have a wear-resistantcoating layer formed on the exposed portion thereof. For example, thewear-resistant coating layer may be a diamond like carbon (DLC) coatinglayer.

DLC coating is performed to deposit a coating layer on the surface of anobject using carbon gas, carbon being the main component of diamonds.The deposited coating layer may have a structure and properties similarto those of diamonds.

Since the DLC coating layer exhibits high hardness similar to that ofdiamonds, therefore, the exposure lens 1110 having the DLC coating layerformed thereon may exhibit high wear resistance.

In the embodiment, the use of an additional cover glass to protect theexposed portion of the lens assembly, i.e. the exposure lens 1100, isobviated. Consequently, the size of a space in which the lens assemblyand the camera module including the same are mounted may be reduced,with the result that the size of a device in which the lens assembly andthe camera module including the same are mounted may be effectivelyreduced.

The second lens unit 1200 may be disposed at the rear of the first lensunit 1100 and the liquid lens unit 1300. Light incident on the firstlens unit 1100 from the outside may pass through the liquid lens unit1300, and may be incident on the second lens unit 1200. The second lensunit 1200 may be disposed in the through-hole formed in the base 1400 soas to be spaced apart from the first lens unit 1100.

The second lens unit 1200 may be constituted by at least one lens.Alternatively, two or more lenses may be aligned in the optical-axisdirection to constitute an optical system. The second lens unit 1200 maybe mounted in the base 1400.

The liquid lens unit 1300 may be disposed between the first lens unit1100 and the second lens unit 1200, and may be mounted in the base 1400.The liquid lens unit 1300 may be provided with a hollow 1310 formed inthe optical-axis direction. The hollow 1310 is a region through whichlight is transmitted after passing through the first lens unit 1100. Atleast a portion of the hollow may be filled with liquid.

In addition, as shown in FIG. 9, the hollow 1310 may be configured suchthat the area of the hollow in the optical-axis direction graduallydecreases from the first lens unit 1100 to the second lens unit 1200.

For example, the hollow 1310 may be filled with two kinds of liquids,i.e. a conductive liquid and a nonconductive liquid. The conductiveliquid and the nonconductive liquid may abut each other in the state ofnot being mixed with each other.

When the conductive liquid is connected to the external power supply andcurrent from the external power supply is supplied to the conductiveliquid, the shape or curvature of the interface between the conductiveliquid and the nonconductive liquid may be changed. The liquid lens unit1300 and the lens assembly and the camera module including the same mayperform auto focusing and handshake compensation by controlling theshape or curvature of the interface between the conductive liquid andthe nonconductive liquid.

As shown in FIG. 9, the first lens unit 1100, the second lens unit 1200,and the liquid lens unit 1300 may be disposed so as to be opposite toeach other in the optical-axis direction. In addition, the focuses ofthe first lens unit 1100, the second lens unit 1200, and the liquid lensunit 1300 may be aligned with each other in the optical-axis directionsuch that the camera module takes a high-quality image.

That the focuses are aligned with each other in the optical-axisdirection may mean that the focuses of the first lens unit 1100, thesecond lens unit 1200, and the liquid lens unit 1300 are arranged on thesame line or are located at least within a designed range, when viewedin the optical-axis direction.

That is, referring to FIG. 9, in the case in which the focus of thefirst lens unit 1100 is located on a phantom line PL that is parallel tothe optical axis, the second lens unit 1200 and the liquid lens unit1300 may be located on the phantom line PL or may deviate from thephantom line PL within a designed range such that the focuses of thelens units may be aligned with each other in the optical-axis direction.

If the focuses of the lens units deviate from the designed range, thequality of a taken image may be deteriorated. Consequently, a focusalignment structure is required. This may be realized by the structureof the base 1400 provided in the embodiment. Hereinafter, the structureof the base 1400 of the embodiment will be described in detail.

The first lens unit 1100, the second lens unit 1200, and the liquid lensunit 1300 may be mounted in the base 1400 so as to be opposite to eachother in the optical-axis direction. The base 1400 may be provided witha space formed therethrough in the optical-axis direction, and the lensunits may be disposed in the space.

The base 1400 may be provided with an insertion hole 1410, through whichthe liquid lens unit 1300 is inserted. That is, the insertion hole 1410,through which the liquid lens unit 1300 is inserted, may be formed inthe edge of the base 1400. As shown in FIG. 9 and FIG. 10, a descriptionof which will follow, the insertion hole 1410 may be formed in one sideof the base 1400 so as to communicate with the space in the base 1400.

As shown in FIG. 9, the liquid lens unit 1300 may be configured suchthat the area of the liquid lens unit in the optical-axis direction isgreater than the area of the first lens unit 1100 or the second lensunit 1200 in the optical-axis direction.

The reason for this is that, in consideration of the structure of theliquid lens unit 1300, the area of the hollow 1310, which is filled withliquid, in the optical-axis direction may be less than the area of thefirst lens unit 1100 or the second lens unit 1200. When the entire areaof the liquid lens unit 1300 in the optical-axis direction is reduced,the area of the hollow 1310 may also be reduced, with the result thatthe area of light that is transmitted through the liquid lens unit 1300may also be reduced.

When the area of the liquid lens unit 1300 through which light istransmitted is reduced, the amount of light that is transmitted throughthe liquid lens unit is reduced, by which the brightness of images thatare taken may be considerably reduced. As a result, there is alimitation on the extent to which both the area of the liquid lens unit1300 through which light is transmitted and the area of the hollow 1310in the optical-axis direction can be reduced.

For the above reason, the area of the liquid lens unit 1300 in theoptical-axis direction may be greater than the area of the first lensunit 1100 or the second lens unit 1200 in the optical-axis direction. Asa result, it is difficult to mount the liquid lens unit 1300 in the base1400 upward from the open bottom of the space in the base 1400, unlikethe first lens unit 1100 or the second lens unit 1200.

In the embodiment, the liquid lens unit 1300 may be mounted in the base1400 through the insertion hole 1410, whereby the lens assembly may beeasily assembled. In addition, the printed circuit board 1500, which iscoupled to the liquid lens unit 1300, may also be easily mounted in thebase 1400.

In addition, the focus of the liquid lens unit 1300 mounted in the base1400 through the insertion hole 1410 may be easily aligned with thefocus of the first lens unit 1100 in the optical-axis direction.

That is, the liquid lens unit 1300 may be moved in the direction that isperpendicular to the optical-axis direction such that the focus of theliquid lens unit 1300 is located on the phantom line PL or is locatedwithin the designed range even though the focus of the liquid lens unit1300 deviates from the phantom line PL.

The printed circuit board 1500 may be connected to the liquid lens unit1300, and at least a portion of the printed circuit board 1500 may beinserted through the insertion hole 1410. The printed circuit board 1500may be provided at both ends thereof with terminals 1510, and may bebent so as to be mounted in the cover member 1600.

The terminals 1510 provided at one end of the printed circuit board 1500may be coupled and connected to the liquid lens unit 1300, and theterminals 1510 provided at the other end of the printed circuit board1500 may be connected to the external power supply.

For connection with the external power supply, the terminals 1510provided at the other end of the printed circuit board may be connectedto a sensor holder 1010, a detailed description of which will follow.

FIG. 10 is an exploded perspective view of FIG. 9. A method ofassembling the lens assembly according to the embodiment and a method ofaligning the focuses of the lens units will be described with referenceto FIG. 10.

First, the first lens unit 1100 is mounted in the base 1400. At thistime, the first lens unit 1100 may be disposed in the space in the base1400 through the opening formed in the lower portion of the base 1400.At this time, the focus of the first lens unit 1100 may be located onthe phantom line PL.

When the first lens unit 1100 is disposed in the space in the base 1400at a designed position, the first lens unit 1100 is coupled to the base1400 using an adhesive.

Subsequently, the liquid lens unit 1300 is mounted in the base 1400. Theliquid lens unit 1300, to which the printed circuit board 1500 iscoupled, may be disposed in the space in the base 1400 through theinsertion hole 1410. At this time, as described above, the liquid lensunit 1300 may be moved in the direction that is perpendicular to theoptical-axis direction to align the focus of the liquid lens unit 1300with the focus of the first lens unit 1100 in the optical-axisdirection.

When the focus alignment is completed, the liquid lens unit 1300 isfinally disposed in the space in the base 1400, and the liquid lens unit1300 is coupled to the base 1400 using an adhesive.

Subsequently, the second lens unit 1200 is mounted in the base 1400. Atthis time, the second lens unit 1200 may be disposed in the space in thebase 1400 through the opening formed in the lower portion of the base1400. The second lens unit 1200 may be moved in the direction that isperpendicular to the optical-axis direction to align the focus of thesecond lens unit 1200 with the focus of the first lens unit 1100 and thefocus of the liquid lens unit 1300 in the optical-axis direction.

When the focus alignment is completed, the second lens unit 1200 isfinally disposed in the space in the base 1400, and the second lens unit1200 is coupled to the base 1400 using an adhesive.

Through the assembly method and the focus alignment method describedabove, the liquid lens unit 1300 may be disposed such that the focus ofthe liquid lens unit is aligned with the focus of the first lens unit1100 in the optical-axis direction. In addition, the second lens unit1200 may be disposed such that the focus of the second lens unit isaligned with the focus of the first lens unit 1100 and the focus of theliquid lens unit 1300 in the optical-axis direction.

In this structure, the focuses of the first lens unit 1100, the secondlens unit 1200, and the liquid lens unit 1300, disposed and mounted inthe base 1400, may be aligned with each other in the optical-axisdirection.

Meanwhile, the area of the hollow 1310 formed in the liquid lens unit1300 may be less than the area of the lens constituting the first lensunit 1100 or the second lens unit 120 in the optical-axis direction.

The reason for this is that the lenses constituting the first lens unit1100 and the second lens unit 120 are configured such that light isincident on the entire area of each lens in the optical-axis direction,whereas the liquid lens unit 1300 is configured such that light isincident only on the hollow 1310 thereof. In order to miniaturize thelens assembly, therefore, the area of the hollow 1310 may be less thanthe area of the first lens unit 1100 or the second lens unit 1200.

The smaller the area of the hollow 1310 in the optical-axis direction,the smaller the amount of light that passes through the hollow 1310. Inthe case in which the liquid lens unit 1300 is disposed in front of thefirst lens unit 1100, therefore, the amount of light that is incident onthe lens assembly is smaller than in the disposition according to theembodiment, i.e. in the case in which the liquid lens unit 1300 isdisposed between the first lens unit 1100 and the second lens unit 1200,with the result that the quality of a taken image may be deteriorated.

Meanwhile, in the case in which the liquid lens unit 1300 is disposed atthe rear of the second lens unit 1200, unlike the disposition of thelens units according to the embodiment, the view angle of the cameramodule may be reduced, since the hollow 1310 has a small area.

In the disposition of the lens units according to the embodiment, i.e.in the case in which the liquid lens unit 1300 is disposed between thefirst lens unit 1100 and the second lens unit 1200, light that has beentransmitted through the hollow 1310 in the liquid lens unit 1300 may berefracted while passing through the second lens unit 1200, which has alarge area. As a result, the view angle may be greater than in the casein which the liquid lens unit 1300 is disposed at the rear of the secondlens unit 1200.

For the above reason, the liquid lens unit 1300 may be disposed betweenthe first lens unit 1100 and the second lens unit 1200, as in theembodiment, thereby realizing a lens assembly configured such that theamount of incident light is not reduced while the view angle is notreduced.

FIG. 11 is a perspective view showing a camera module according to anembodiment. FIG. 12 is a view showing the internal structure of FIG. 11.As shown in FIGS. 11 and 12, the lens assembly of the embodiment mayfurther include a cover member 1600.

The cover member 1600 may receive the base 1400 and the printed circuitboard 1500. Consequently, the cover member may receive the first lensunit 1100, the second lens unit 1200, and the liquid lens unit 1300,mounted in the base 1400, to protect the lens units.

In an embodiment, the cover member 1600 may be formed in a hollow shapehaving an open lower portion and a through-hole, through which the frontportion of the first lens unit 1100 is exposed.

As shown in FIGS. 11 and 12, the camera module according to theembodiment may include the lens assembly having the above structure, animage sensor 1011, and a sensor holder 1010.

The image sensor 1011 is a region which is disposed opposite to the lensassembly in the optical-axis direction and on which light that has beensequentially transmitted through the first lens unit 1100, the liquidlens unit 1300, and the second lens unit 1200 is incident to formimages.

Meanwhile, although not shown, a filter for improving the quality of ataken image may be provided between the second lens unit 1200 and theimage sensor 1011. For example, the filter may be an infrared cutofffilter.

The image sensor 1011 may be mounted on the sensor holder 1010, and maybe coupled to the base 1400. In addition, various elements for operatingthe camera module may be mounted to the sensor holder 1010. In addition,the sensor holder 1010 may be connected to the printed circuit board1500.

That is, connection portions (not shown) configured to be connected tothe terminals 1510 formed at the printed circuit board 1500 may beformed at the sensor holder 1010. The terminals 1510 and the connectionportions may be coupled to each other by soldering or using a conductiveadhesive.

In addition, the sensor holder 1010 may be provided with a connector1012 for connection with the external power supply. Consequently, theliquid lens unit 1300 may be connected to the external power supply viathe printed circuit board 1500, the sensor holder 1010, and theconnector 1012 so as to be driven by current from the external powersupply.

FIG. 13 is a perspective view showing a camera module provided with acover member 1600 according to another embodiment. FIG. 14 is a viewshowing the state in which the camera module of FIG. 13 is mounted in adevice.

As shown in FIGS. 13 and 14, the cover member 1600 may be provided witha protrusion core 1610. The protrusion core 1610 may be configured tohave a structure in which the circumference of the through-hole formedin the cover member 1600 protrudes in the optical-axis direction suchthat the exposed portion of the first lens unit 1100, i.e. the exposurelens 1110, is exposed to the outside.

Meanwhile, the front portion of the base 1400 may protrude in responseto the shape of the protrusion core 1610. As shown in FIG. 13, a spacemay be defined in the protrusion core 1610, and the first lens unit 1100may be mounted in the space.

As shown in FIG. 14, the protrusion core 1610 may be inserted into anopening formed in a cover 1020 of the device. In this structure, thespace in the device in which the lens assembly and the camera moduleincluding the same are disposed may be reduced by changing the shape ofthe cover member 1600 and the shape of the base 1400 without reducingthe overall length of the lens assembly of the embodiment in theoptical-axis direction, in contrast with the structure of the lensassembly described with reference to FIGS. 9 to 12.

The base 1400 described with reference to FIGS. 9 to 14 may be definedas a holder. In the case in which the insertion hole 1410 includes twoholes that face each other, the holes may be defined as a first hole anda second hole.

Hereinafter, an optical device according to this embodiment will bedescribed.

The optical device may be a mobile phone, a smartphone, a portable smartdevice, a digital camera, a laptop computer, a digital broadcastingterminal, a personal digital assistant (PDA), a portable multimediaplayer (PMP), or a navigator. However, the disclosure is not limitedthereto. Any device that takes video or still images may be used.

The optical device may include a main body (not shown), a display unit(not shown), and a camera module 2000 or 2001.

The main body may define the external appearance of the optical device.In an example, the main body may be formed in the shape of a rectangularcube. However, the disclosure is not limited thereto. In anotherexample, at least a portion of the main body may be round. The main bodymay receive the camera module 2000 or 2001. The display unit may bedisposed at one surface of the main body.

The camera module 2000 or 2001 may be disposed at the main body. Thecamera module 2000 or 2001 may be disposed at one surface of the mainbody. At least a portion of the camera module 2000 or 2001 may bereceived in the main body. The camera module 2000 or 2001 may takeimages of a subject.

The display unit may be disposed at the main body. The display unit maybe disposed at one surface of the main body. That is, the display unitmay be disposed at the same surface as the camera module 2000 or 2001.Alternatively, the display unit may be disposed at a surface differentfrom the one surface of the main body.

The display unit may be disposed at the surface that is opposite to thesurface at which the camera module 2000 or 2001 is disposed. The displayunit may output the image taken by the camera module 2000 or 2001.

Hereinafter, the structure of a camera module 2000 according to a firstembodiment will be described with reference to the drawings.

FIG. 16 is a perspective view showing a camera module according to firstand second embodiments, FIG. 17 is an exploded perspective view showingthe camera module according to the first embodiment, FIG. 18 is aperspective view showing a shield can according to a first embodiment,FIG. 19 is a perspective view showing a lens holder according to a firstembodiment, FIG. 20 is a sectional view showing the lens holderaccording to the first embodiment, FIG. 21 is an exploded perspectiveview showing a liquid lens according to a first embodiment, FIG. 22 is aplan view showing the liquid lens according to the first embodiment,FIGS. 23A to 23L are conceptual sectional views showing that aconductive liquid and a nonconductive liquid are received in a cavity infirst and second embodiments, and FIG. 24 is a sectional view showingthe camera module according to the first embodiment.

The camera module 2000 according to the first embodiment may be a cameramodule for AF. The camera module 2000 may be referred to as an “AFcamera module.” Alternatively, the camera module 2000 may be configuredas a camera module for OIS.

The camera module 2000 may include a cover member 2100, a lens module,an infrared filter 2600, a main board 2700, an image sensor (not shown),and a controller (not shown). However, one or more selected from amongthe cover member 2100, the infrared filter 2600, the main board 2700 andthe image sensor (not shown) may be omitted from the camera module 2000,or may be changed.

The cover member 2100 may define the external appearance of the cameramodule 2000. The cover member 2100 may be formed in the shape of ahexahedron having an open lower portion. However, the disclosure is notlimited thereto. The cover member 2100 may be a nonmagnetic body.Alternatively, the cover member 2100 may be made of a metal sheet. Inthis case, the cover member 2100 may shield electromagnetic interference(EMI). Because of this characteristic of the cover member 2100, thecover member 2100 may be referred to as an “EMI shield can.” The covermember 2100 may inhibit electromagnetic waves generated outside thecamera module 2000 from being introduced into the inside of the covermember 2100. In addition, the cover member 2100 may inhibitelectromagnetic waves generated inside the cover member 2100 from beingdischarged to the outside of the cover member 2100. However, thematerial for the cover member 2100 is not limited to the metal sheet.

The cover member 2100 may include an upper plate 2120 and a plurality ofside plates 2130. The cover member 2100 may include an upper plate 2120and a plurality of side plates 2130 extending downward from the outsideof the upper plate 2120. The cover member 2100 may be located at theouter surface of the lens holder 2200. The cover member 2100 may abutthe outer surface of the lens holder 2200. The lower ends of the sideplates 2130 of the cover member 2100 may be mounted to the lens holder2200. The lower ends of the side plates 2130 of the cover member 2100may be mounted to a stair portion 2250 formed at the lower portion ofthe lens holder 2200.

The upper plate 2120 may be formed in the shape of a plate. The sideplates 2130 may extend downward from respective sides of the upper plate2120. In this case, the side plates 2130 may be integrally formed withthe upper plate 2120. The upper plate 2120 may be provided in the centerthereof with a first transmission window 2110. The first transmissionwindow 2110 may be a circular hole formed in the center of the upperplate 2120, and the optical axis of the lens module, a description ofwhich will follow, may extend through the center of the firsttransmission window 2110. Consequently, the light reflected by a subjectmay be radiated to the lens module through the first transmission window2110.

Several side plates 2130 may be provided. The side plates 2130 mayextend downward from four sides of the upper plate 2120. Consequently,the number of side plates 2130 may be four. In addition, the side plates2130 may be spaced apart from each other. The lower ends of the sideplates 2130 may be mounted to the stair portion 2250, formed at thelower portion of the lens holder 2200.

Slits 2140 may be spaces between the respective side plates 2130. Thatis, the slits 2140 may be located between neighboring ones 2130 of theside plates 2130. The slits 2140 may be located along four verticalsides of the cover member 2100.

Each slit 2140 may include first, second, and third gaps 2142, 2144, and2146. The first gap 2142 may be formed along each vertical side of thecover member 2100. In addition, the upper end of the first gap 2142 maybe divided into two parts at each upper corner of the cover member 2100in order to form the second and third gaps 2144 and 2146. The upper endsof the second and third gaps 2144 and 2146 may be round. As a result,the cover member 2100 may be formed from a single flat sheet in adeveloped state, and the side plates 2130 may be bent downward to formthe cover member 2100. In this case, the side plates 2130 may be easilybent, since the upper ends of the second and third gaps 2144 and 2146are round. Furthermore, stress is inhibited from being concentrated atboth ends of the bent portions of the side plates 2130, therebyinhibiting the occurrence of cracks.

The lens module may include a lens holder 2200, a first lens unit 2300,a liquid lens 2400, and a second lens unit 2500. The main board 2700 maybe located at the lower side of the lens module. The lens module may besupported by the main board 2700. The lower end of the lens module maybe mounted to the main board 2700. The lower end of the lens module maybe mounted to the outside of the upper surface of the main board 2700.Light that has been transmitted through the lens module may be radiatedto the image sensor, which is mounted on the inside of the upper surfaceof the main board 2700. In a modification (not shown), the lens modulemay include a base plate. In this case, the lower end of the lens modulemay be mounted to the base plate so as to be supported by the baseplate. In addition, the main board may be located under the base plate.Furthermore, the base plate may be mounted to the outside of the uppersurface of the main board.

The lens holder 2200 may be a block-shaped plastic mold. The lens holder2200 may be manufactured by hole molding. The lens holder 2200 may beprovided in the center thereof with a hole 2210 formed in theoptical-axis direction. The lens holder 2200 may be provided with a hole2210 formed through the center of the lens holder 2200 in theoptical-axis direction.

The hole 2210 may be located in the lens holder 2200. The hole 2210 maybe formed in the center of the lens holder 2200 in the optical-axisdirection. The hole 2210 may be formed through the lens holder 2200 inthe upward-downward direction. Consequently, the upper side and thelower side of the lens holder 2200 may be open through the hole 2210.The first lens unit 2300, the liquid lens 2400, and the second lens unit2500 may be received in the hole 2210.

The hole 2210 may include a second transmission window 2211, a firstlens receiving hole 2220, a second lens receiving hole 2230, aninsertion hole 2232, and a third lens receiving hole 2240. The hole 2210may be configured such that the second transmission window 2211, thefirst lens receiving hole 2220, the second lens receiving hole 2230, andthe third lens receiving hole 2240 are sequentially located in thatorder from top and bottom. The first lens unit 2300, the liquid lens2400, and the second lens unit 2500 may be sequentially received in thehole 2210 in that order from top and bottom. In this case, the opticalaxes of the first lens unit 2300, the liquid lens 2400, and the secondlens unit 2500 may be aligned with one another.

The second transmission window 2211 may be located at the uppermost sideof the hole 2210. The second transmission window 2211 may be circular.The second transmission window 2211 may be located under the firsttransmission window 2110 so as to be spaced apart from the firsttransmission window 2110. The first lens receiving hole 2220 may belocated at the lower side of the second transmission window 2211.

The second transmission window 2211 and the first lens receiving hole2220 may communicate with each other in the upward-downward direction.The second transmission window 2211 may be integrally formed with thefirst lens receiving hole 2220. That is, the second transmission window2211 may be a portion of the first lens receiving hole 2220. In thiscase, the uppermost lens of the first lens unit 2300 may protrudethrough the second transmission window 2211.

The first lens receiving hole 2220 may be located in the center of thehole 2210. The second transmission window 2211 may be located at theupper side of the first lens receiving hole 2220. The second lensreceiving hole 2230 may be located at the lower side of the first lensreceiving hole 2220. The second transmission window 2211, the first lensreceiving hole 2220, and the second lens receiving hole 2230 maycommunicate with each other in the upward-downward direction. The secondtransmission window 2211, the first lens receiving hole 2220, and thesecond lens receiving hole 2230 may be aligned with one another in theoptical-axis direction. The first lens unit 2300 may be received in thefirst lens receiving hole 2220.

The second lens receiving hole 2230 may be located at the middle of thehole 2210. The first lens receiving hole 2220 may be located at theupper side of the second lens receiving hole 2230. The third lensreceiving hole 2240 may be located at the lower side of the second lensreceiving hole 2230. The first lens receiving hole 2220, the second lensreceiving hole 2230, and the third lens receiving hole 2240 maycommunicate with each other in the upward-downward direction. The firstlens receiving hole 2220, the second lens receiving hole 2230, and thethird lens receiving hole 2240 may be aligned with one another in theoptical-axis direction. The liquid lens 2400 may be received in thesecond lens receiving hole 2230. As a result, the optical axes of thefirst lens unit 2300 and the liquid lens 2400 may be aligned with eachother.

The insertion hole 2232 may be formed in the side surface of the lensholder 2200. The insertion hole 2232 may be formed in the lens holder2200 so as to be inclined with respect to the optical-axis direction.The insertion hole 2232 may be formed from the surface of the lensholder 2200 to the hole 2210 so as to be inclined with respect to theoptical-axis direction. The insertion hole 2232 may be formed from thesurface of the lens holder 2200 to the hole 2210 so as to beperpendicular to the optical-axis direction. The insertion hole 2232 maybe formed through one side of the lens holder 2200 so as to be inclinedwith respect to the optical-axis direction. The insertion hole 2232 maybe formed through one side of the lens holder 2200 so as to beperpendicular to the optical-axis direction. That is, a portion of oneside of the lens holder 2200 may be open through the insertion hole2232. The insertion hole 2232 may communicate with the hole 2210. Theinsertion hole 2232 may communicate with the second lens receiving hole2230. As a result, the liquid lens 2400 may be laterally inserted intothe lens holder 2200 through the insertion hole 2232 so as to bereceived in the second lens receiving hole 2230. A board receivingrecess 2234 extending downward to communicate with the insertion hole2232 may be formed in one side of the lens holder 2200 through which theinsertion hole 2232 is formed. An upper connection board 2410 b and alower connection board 2450 b, a description of which will follow, maybe received in the board receiving recess 2234. The board receivingrecess 2234 may extend to the lower end of the lens holder 2200. Sincethe upper connection board 2410 b and the lower connection board 2450 bare located along the board receiving recess 2234, the upper connectionboard 2410 b and the lower connection board 2450 b may be connected tothe main board 2700 located under the lens holder 2200.

The third lens receiving hole 2240 may be disposed in the hole 2210. Thesecond lens receiving hole 2230 may be located at the upper side of thethird lens receiving hole 2240. The second lens receiving hole 2230 andthe third lens receiving hole 2240 may communicate with each other inthe upward-downward direction. The second lens receiving hole 2230 andthe third lens receiving hole 2240 may be aligned with each other in theoptical-axis direction. The second lens unit 2500 may be received in thethird lens receiving hole 2240. As a result, the optical axes of theliquid lens 2400 and the second lens unit 2500 may be aligned with eachother.

Generally, the size of the liquid lens 2400 is greater than the size ofeach of the other lenses. When the liquid lens 2400 is inserted throughthe lower opening of the hole 2210, therefore, an upper hole forreceiving the first lens unit 2300 and the liquid lens 2400 and a lowerhole for receiving the second lens unit 2500 are needed. Since the holesare formed through separate hole molding processes, the optical axes ofthe upper hole and the lower hole may not be aligned with each other. Inthe first embodiment, however, the liquid lens 2400 is insertedlaterally through the insertion hole 2232. As a result, all of the firstlens unit 2300, the liquid lens 2400, and the second lens unit 2500 maybe received in a single hole 2210. That is, all lenses are received in asingle hole 2210 formed through a single hole molding process, with theresult that optical-axis twisting does not occur.

The first lens unit 2300 may include one or more lenses. The first lensunit 2300 may include two lenses. The lenses of the first lens unit 2300may be located in the state of being stacked. The first lens unit 2300may be received in the first lens receiving hole 2220. The lenses of thefirst lens unit 2300 may be configured such that the upper portion ofeach lens abuts the stair of the first lens receiving hole 2220 or anO-ring and such that the lower portion of each lens is supported andfixed by the lower lens or an O-ring. The lower portion of the lowermostlens of the first lens unit 2300 may abut the upper surface of an upperplate 2420 of the liquid lens 2400, a description of which will follow.The lower portion of the lowermost lens of the first lens unit 2300 maybe supported and fixed by the upper surface of the upper plate 2420 ofthe liquid lens 2400, a description of which will follow.

An inclined portion 2310 may be located along the outer circumference ofthe lower surface of the lowermost lens of the first lens unit 2300. Inthis case, the inclined portion 2310 may be formed so as to be inclineddownward toward the side of the lens holder 2200. In the case in whichthe outer circumference of the lower surface of the lowermost lens isangled, there may be friction with the upper plate 2420 when the liquidlens 2400 is inserted. In order to inhibit this, the inclined portion2310 is required.

The liquid lens 2400 is a lens that controls the curvature of theinterface between a conductive liquid and a nonconductive liquid toperform AF and OIS functions. When the conductive liquid and thenonconductive liquid are received, an electrode and an insulator arestacked, and voltage is applied to the electrode, an electrowettingphenomenon, in which the contact angle between the conductive liquid andthe inner surface of the cavity coated with the insulator is changeddepending on the magnitude of the applied voltage, occurs. Theelectrowetting phenomenon will be described in more detail withreference to FIG. 15. When a conductive liquid drop 2040 is dropped tothe upper surface of an insulation film 2014, which is electricallyinsulated, the conductive liquid drop has a spherical shape, asindicated by the solid line in FIG. 15. When voltage is applied to asecond electrode 2015 between a first electrode 2013 under theinsulation film 2014 and the conductive liquid drop 2040, anelectrowetting phenomenon, in which the contact angle between theconductive liquid drop 2040 and the upper surface of the insulation film2013 is changed, occurs, as indicated by the dotted line in FIG. 15.Furthermore, when the position to which voltage is applied is changed,the position at which the electrowetting phenomenon occurs is changed.In the liquid lens 2400, the curvature of the interface between theconductive liquid and the nonconductive liquid is changed due to theelectrowetting phenomenon, and the AF and OIS functions may be performedby controlling the curvature of the interface.

In the following description, the liquid lens 2400 according to thefirst embodiment is configured such that an upper electrode unitincludes first to fourth electrodes a1, a2, a3, and a4 and such that aninner wall electrode unit includes fifth to eighth electrodes a5, a6,a7, and a8.

The liquid lens 2400 may be located in the lens holder 2200. The liquidlens 2400 may be received in the hole 2210. The liquid lens 2400 may bereceived in the second lens receiving hole 2230 through the insertionhole 2232. The liquid lens 2400 may be configured such that the upperportion of the liquid lens abuts the lower surface of the lowermost lensof the first lens unit 2300 and the upper surface of the second lensreceiving hole 2230 and such that the lower portion of the liquid lensis supported and fixed by the upper surface of the uppermost lens of thesecond lens unit 2500 and the lower surface of the second lens receivinghole 2230. The liquid lens 2400 may be inserted through one side of thelens holder 2200 so as to be received in the hole 2210. The liquid lens2400 may be received in the second lens receiving hole 2230 through theinsertion hole 2232. The liquid lens 2400 may be connected to the mainboard 2700. The curvature of the interface of the liquid lens 2400 maybe controlled.

The liquid lens 2400 may be located in the lens holder 2200. The liquidlens 2400 may be received in the hole 2210. The liquid lens 2400 may bereceived in the second lens receiving hole 2230 through the insertionhole 2232. The liquid lens 2400 may be configured such that the upperportion of the liquid lens abuts the lower surface of the lowermost lensof the first lens unit 2300 and the upper surface of the second lensreceiving hole 2230 and such that the lower portion of the liquid lensis supported and fixed by the upper surface of the uppermost lens of thesecond lens unit 2500 and the lower surface of the second lens receivinghole 2230. The liquid lens 2400 may be inserted through one side of thelens holder 2200 so as to be received in the hole 2210. The liquid lens2400 may be received in the second lens receiving hole 2230 through theinsertion hole 2232. The liquid lens 2400 may be connected to the mainboard 2700. The curvature of the interface of the liquid lens 2400 maybe controlled.

The liquid lens 2400 may be configured such that boards and plates arestacked. The liquid lens 2400 may include an upper board 2410, an upperplate 2420, a core plate 2430, a lower plate 2440, and a lower board2450.

The upper board 2410 may be an upper portion of the liquid lens 2400.The upper plate 2420 may be located under the upper board 2410. Theupper plate 2420 may be located between the upper board 2410 and thecore plate 2430. The upper surface of the upper board 2410 may abut theupper inner wall of the second lens receiving hole 2230. The upper board2410 may be connected to electrodes disposed on the core plate 2430. Theupper board 2410 may be connected to the main board 2700. The upperboard 2410 may supply power to an electrode unit a of the core plate2430, a description of which will follow, under the control of the mainboard 2700. The upper board 2410 may change the direction, intensity,and wavelength of the current that is supplied to the electrode unit aand the position to which the current is supplied.

The upper board 2410 may include an upper circuit board 2410 a and anupper connection board 2410 b.

The upper circuit board 2410 a may be a printed circuit board (PCB). Theupper circuit board 2410 a may be formed in the shape of a plate. Theupper circuit board 2410 a may be formed in the shape of a quadrangularplate.

The upper circuit board 2410 a may be provided at a portion thereofcorresponding to (opposite to) a cavity 2431, a description of whichwill follow, or a portion thereof radially extending from the portionthereof corresponding to (opposite to) the cavity 2431 with an upperguide hole 2415 extending to one side. The one side may be the sidelocated at the entrance in the direction in which the liquid lens 2400is inserted through the insertion hole 2232. When the liquid lens 2400is inserted, therefore, the friction between the lower surface of thelowermost lens of the first lens unit 2300 and the upper circuit board2410 a may be minimized. The lower surface of the lowermost lens of thefirst lens unit 2300 may be supported by the upper guide hole 2415 inthe state of abutting the upper plate 2420. As a result, the lens of thefirst lens unit 2300, which has already been inserted, may be fixed at apredetermined position without moving. Furthermore, the upper circuitboard 2410 a may be inhibited from being worn or from being separatedfrom the upper plate 2420 or the core plate 2430 due to friction causedwhen the liquid lens 2400 is inserted.

The upper circuit board 2410 a may be provided with a first upper corner2411, a second upper corner 2412, a third upper corner 2413, and afourth upper corner 2414, which are arranged in the counterclockwisedirection. The first to fourth upper corners 2411, 2412, 2413, and 2414may be located further inward than the corners of the core plate 2430.That is, the corners of the upper board 2410 may be located inward fromthe corners of the core plate 2430. When the liquid lens 2400 isinserted, therefore, the friction between the first to fourth uppercorners 2411, 2412, 2413, and 2414 and the upper inner wall and the sidewall of the second lens receiving hole 2230 may be minimized. As aresult, the first to fourth upper corners 2411, 2412, 2413, and 2414 maybe inhibited from being separated from the core plate 2430, whereby theupper circuit board 2410 a may be inhibited from being separated fromthe core plate 2430. In a modification (not shown), the sides of theupper circuit board 2410 a may be located further inward than the sidesof the core plate 2430.

The first to fourth upper corners 2411, 2412, 2413, and 2414 may beconnected to the core plate 2430. The first to fourth upper corners2411, 2412, 2413, and 2414 may be connected to the electrode unit a ofthe core plate 2430 corresponding thereto (opposite thereto). The firstupper corner 2411 may be connected to the first electrode a1. The secondupper corner 2412 may be connected to the second electrode a2. The thirdupper corner 2413 may be connected to the third electrode a3. The fourthupper corner 2414 may be connected to the fourth electrode a4. The firstto fourth upper corners 2411, 2412, 2413, and 2414 may be connected tothe first to fourth electrodes a1, a2, a3, and a4 via four upperconduction portions (not shown). In this case, the upper conductionportions (not shown) may extend through first to fourth upper recesses2421, 2422, 2423, and 2424 corresponding to (opposite to) the first tofourth upper corners 2411, 2412, 2413, and 2414, a description of whichwill follow. In addition, each of the upper conduction portions may beconductive epoxy. As a result, the first to fourth upper corners 2411,2412, 2413, and 2414 may be adhered to the first to fourth electrodesa1, a2, a3, and a4 via the conductive epoxy. In addition, each of theupper conduction portions may be an electrode pad.

In a modification (not shown), recesses may be formed in the sides ofthe upper plate. The recesses formed in the upper plate may be concavetoward the inside of the core plate.

The upper connection board 2410 b may be a flexible printed circuitboard (FPCB). The upper connection board 2410 b may be connected to theupper circuit board 2410 a. The upper connection board 2410 b may beconnected to the main board 2700. As a result, the main board 2700 maysupply power to the first to fourth electrodes a1, a2, a3, and a4 viathe upper connection board 2410 b and the upper circuit board 2410 a.

The upper connection board 2410 b may extend downward from the otherside of the upper circuit board 2410 a. The other side may be a sidelocated at the end in the direction in which the liquid lens 2400 isinserted through the insertion hole 2232. The junction between the upperconnection board 2410 b and the upper circuit board 2410 a may be round.The upper connection board 2410 b may be received in the board receivingrecess 2234, and may extend downward. In this case, the upper connectionboard 2410 b may be protected from the outside, since the cover member2100 is located outside the upper connection board.

The upper plate 2420 may be located under the upper board 2410. Theupper plate 2420 may abut the upper board 2410. The upper plate 2420 maybe located on the core plate 2430. The upper plate 2420 may abut thecore plate 2430. The upper surface of the upper plate 2420 may abut thelower surface of the lowermost lens of the first lens unit 2300extending through a first guide hole 2415. As a result, the lowermostlens of the first lens unit 2300 may be supported by the upper plate2420.

The upper plate 2420 may be made of a transparent material. The upperplate 2420 may be insulative. The upper plate 2420 may be made of aglass material. The upper plate 2420 may have an antireflection coatingsurface. The upper plate 2420 may cover the upper portion of the cavity2431, a description of which will follow. Consequently, the upper plate2420 may be referred to as a cover glass. A fifth upper recess 2425 maybe located in the center of the lower surface of the upper plate 2420.As will be described below, in the first embodiment, a conductive liquidL1 is located in the upper portion of the cavity 2431 and anonconductive liquid L2 is located in the lower portion of the cavity2431, with the result that the fifth upper recess 2425 may be filledwith the conductive liquid L1 received in the cavity 2431. The fifthupper recess 2425 may correspond to (may be opposite to) an insulationportion b coated in a ring shape on the upper surface of the middleplate 2430, a description of which will follow. The area of the fifthupper recess 2425 may be greater than the area of the insulation portionb coated in the ring shape on the upper surface of the middle plate2430. As a result, the conductive liquid in the fifth upper recess 2425may abut the first to fourth electrodes a1, a2, a3, and a4.

The upper plate 2420 may be provided at the angular points, the outercircumference, or the corners thereof with a first upper recess 2421, asecond upper recess 2422, a third upper recess 2423, and a fourth upperrecess 2424, which are arranged in the counterclockwise direction. Thecorners of the upper plate 2420 may be cut inward to form the firstupper recess 2421, the second upper recess 2422, the third upper recess2423, and the fourth upper recess 2424 in the counterclockwisedirection. The first to fourth upper recesses 2421, 2422, 2423, and 2424may be located between the first to fourth upper corners 2411, 2412,2413, and 2414 and the first to fourth electrodes a1, a2, a3, and a4.The first to fourth upper corners 2411, 2412, 2413, and 2414 may beconnected to the first to fourth electrodes a1, a2, a3, and a4 via thefirst to fourth upper recesses 2421, 2422, 2423, and 2424. The first tofourth upper corners 2411, 2412, 2413, and 2414 may be connected to thefirst to fourth electrodes a1, a2, a3, and a4 via the upper conductionportions (not shown) extending through the first to fourth upperrecesses 2421, 2422, 2423, and 2424. In this case, each of the upperconduction portions may be conductive epoxy. In addition, each of theupper conduction portions may be an electrode pad.

The core plate 2430 may be located under the upper plate 2420. The coreplate 2430 may abut the upper plate 2420. The core plate 2430 may belocated on the lower plate 2440. The core plate 2430 may abut the lowerplate 2440. The core plate 2430 may be provided in the center thereofwith a cavity 2431. A first liquid L1 and a second liquid L2 may bereceived in the cavity 2431. The core plate 2430 may be provided with acavity 2431 formed through the center of the core plate 2430. Anelectrode unit a may be coated on the surface of the core plate 2430 andon the inner surface of the cavity 2431. The upper electrode unit may bedisposed at the upper portion of the core plate 2430. The upperelectrode unit may include first to fourth electrodes a1, a2, a3, anda4, which are separated from each other. An inner wall electrode unit,which extends to the upper portion of the core plate 2430 and the lowerportion of the core plate 2430, may be disposed on the inner wall of thecavity 2431. The inner wall electrode unit may include fifth to eighthelectrodes a5, a6, a7, and a8, which are separated from each other. Theupper electrode unit and the inner wall electrode unit may beinterrupted at the upper portion (the upper surface) of the core plate2430. The electrode unit a on the inner wall of the cavity 2431 may becoated with an insulation layer b. In addition, the electrode unit a onthe upper surface of the core plate 2430 around the cavity 2431 may becoated with an insulation layer b. The core plate 2430 may be connectedto the upper board 2410. The core plate 2430 may be connected to thelower board 2450.

The cavity 2431 may be located in the core plate 2430. The cavity 2431may be located in the center of the core plate 2430. The cavity 2431 maybe formed through the core plate 2430. The cavity 2431 may be configuredsuch that the width of the cavity decreases from top to bottom. Thecavity 2431 may be configured such that the horizontal sectional area ofthe cavity decreases from top to bottom. The first liquid L1 and thesecond liquid L2 may be received in the cavity 2431. The electrode unita may be coated on the inner wall of the cavity 2431. The inner wallelectrodes a5, a6, a7, and a8 may be coated on the inner wall of thecavity 2431.

The electrode unit a may be made of a conductive metal. The electrodeunit a may include an upper electrode unit and an inner wall electrodeunit. The upper electrode unit may include first to fourth electrodesa1, a2, a3, and a4. The inner wall electrode unit may include fifth toeighth electrodes a5, a6, a7, and a8. The electrode unit a may be coatedon the surface of the core plate 2430. The electrode unit a may beconnected to the upper board 2410. The electrode unit a may be connectedto the upper board 2410 via upper conduction portions (not shown). Inthis case, each of the upper conduction portions may be conductiveepoxy. In addition, each of the upper conduction portions may be anelectrode pad. The electrode unit a may be connected to the lower board2450. The electrode unit a may be connected to the lower board 2450 vialower conduction portions (not shown). In this case, each of the lowerconduction portions may be conductive epoxy or an electrode pad.

The first to fourth electrodes a1, a2, a3, and a4 (the upper electrodeunit) may be disposed on the upper portion (the upper surface) of thecore plate 2430. Furthermore, the first to fourth electrodes a1, a2, a3,and a4 may abut the first liquid L1 to apply voltage to the first liquidL1. The first to fourth electrodes a1, a2, a3, and a4 may divide theupper portion (the upper surface) of the core plate 2430 into foursectors in the counterclockwise direction.

The fifth to eighth electrodes a5, a6, a7, and a8 (the inner wallelectrode unit) may be disposed on the inner wall of the cavity 2431 andthe lower surface and the upper surface of the core plate 2430. Thefifth to eighth electrodes a5, a6, a7, and a8 may divide the inner wallof the cavity 2431 and the lower surface and the upper surface of thecore plate 2430 into four sectors in the counterclockwise direction. Theinsulation layer b may be interposed between the fifth to eighthelectrodes a5, a6, a7, and a8 (the inner wall electrode unit) and thefirst and second liquids L1 and L2. That is, the fifth to eighthelectrodes a5, a6, a7, and a8 (the inner wall electrode unit) do notabut the first and second liquids L1 and L2.

The first to fourth electrodes a1, a2, a3, and a4 (the upper electrodeunit) and the fifth to eighth electrodes a5, a6, a7, and a8 (the innerwall electrode unit) may not be connected to each other on the upperportion (the upper surface) of the core plate 2430. That is, the firstto fourth electrodes a1, a2, a3, and a4 (the upper electrode unit) andthe fifth to eighth electrodes a5, a6, a7, and a8 (the inner wallelectrode unit) may be interrupted on the upper portion of the coreplate 2430.

The corners of the first to fourth electrodes a1, a2, a3, and a4 maycorrespond to (may be opposite to) the first to fourth upper corners2411, 2412, 2413, and 2414 of the upper board 2410, respectively. Thefirst to fourth upper corners 2411, 2412, 2413, and 2414 of the upperboard 2410 may be connected to corners of the first to fourth electrodesa1, a2, a3, and a4 corresponding thereto (opposite thereto) via the fourupper conduction portions. In this case, the first electrode a1 and thefirst upper corner 2411 may be connected to each other via the upperconduction portion extending (passing) through the first upper recess2421. In addition, the second electrode a2 and the second upper corner2412 may be connected to each other via the upper conduction portionextending (passing) through the second upper recess 2422. In addition,the third electrode a3 and the third upper corner 2413 may be connectedto each other via the upper conduction portion extending (passing)through the third upper recess 2423. In addition, the fourth electrodea4 and the fourth upper corner 2414 may be connected to each other viathe upper conduction portion extending (passing) through the fourthupper recess 2424. In this case, each of the upper conduction portionsmay be conductive epoxy or an electrode pad. As a result, power may besupplied to the first to fourth electrodes a1, a2, a3, and a4 via theupper board 2410. Furthermore, power may be supplied to only some of thefirst to fourth electrodes a1, a2, a3, and a4. In addition, theintensity and polarity of the power supplied to the first to fourthelectrodes a1, a2, a3, and a4 may be controlled.

The corners of the fifth to eighth electrodes a5, a6, a7, and a8 maycorrespond to (may be opposite to) first to fourth lower corners 2451,2452, 2453, and 2454 of the lower board 2450, respectively. The first tofourth lower corners 2451, 2452, 2453, and 2454 of the lower board 2450may be connected to the corners of the fifth to eighth electrodes a5,a6, a7, and a8 corresponding thereto (opposite thereto) via four lowerconduction portions (not shown). In this case, the fifth electrode a5and the first lower corner 2451 may be connected to each other via alower conduction portion extending (passing) through a first lowerrecess 2441. In addition, the sixth electrode a6 and the second lowercorner 2452 may be connected to each other via a lower conductionportion extending (passing) through a second lower recess 2442. Inaddition, the seventh electrode a7 and the third lower corner 2453 maybe connected to each other via a lower conduction portion extending(passing) through a third lower recess 2443. In addition, the eighthelectrode a8 and the fourth lower corner 2454 may be connected to eachother via a lower conduction portion extending (passing) through afourth lower recess 2444. In this case, each of the lower conductionportions may be conductive epoxy or an electrode pad. As a result, powermay be supplied to the fifth to eighth electrodes a5, a6, a7, and a8 viathe lower board 2450. Furthermore, power may be supplied to only some ofthe fifth to eighth electrodes a5, a6, a7, and a8. In addition, theintensity and polarity of the power supplied to the fifth to eighthelectrodes a5, a6, a7, and a8 may be controlled.

The insulation layer b may be made of an insulative polymer. Theinsulation layer b may be a parylene coating. The insulation layer b maybe made of an insulative (nonconductive) oxide. The insulation layer bmay be coated on the electrode unit a. The insulation layer b may becoated on the electrode unit a by stacking. The insulation layer b maybe coated on the electrode unit a along the inner wall of the cavity2431. The insulation layer b may be coated on the lower plate 2440opposite to the cavity 2431. In this case, the insulation layer b mayabut the upper surface of the lower plate 2440. In addition, theinsulation layer b may abut a fifth lower recess 2445 of the lower plate2440, a description of which will follow. The insulation layer b may becoated on the electrode unit a along the circumference of the cavity2431 on the upper surface of the core plate 2430. The insulation layer bdisposed on the inner wall of the cavity 2431, the insulation layer bdisposed on the lower plate 2440, and the insulation layer b disposedalong the circumference of the cavity 2431 on the upper surface of thecore plate 2430 may be integrally formed. As a result, the insulationlayer b may abut the first liquid L1 and the second liquid L2, and mayreceive the first liquid L1 and the second liquid L2. The thickness ofthe insulation layer b may be 200 nm or more. Particularly, if thethickness of the insulation layer b disposed on the lower plate 2440 isless than 200 nm, the insulation layer b may be worn during the usethereof, which is undesirable. The light transmittance of the insulationlayer b may be 85% or more. In particular, for light having a wavelengthof 430 nm to 680 nm, the transmittance of the insulation layer b may be85% or more. If the transmittance of the insulation layer is less than85%, the amount of light that is radiated to the image sensor is notsufficient, whereby the resolution of output images or video is reduced.

The lower plate 2440 may be located on the lower board 2450. The lowerplate 2440 may abut the lower board 2450. The lower plate 2440 may belocated under the core plate 2430. The lower plate 2440 may abut thecore plate 2430. The lower surface of the lower plate 2440 may abut theupper surface of the uppermost lens of the second lens unit 2500extending through a second guide hole 2455. As a result, the uppermostlens of the second lens unit 2500 may be supported by the lower plate2440. In a modification (not shown), recesses may be formed in the sidesof the lower plate. The recesses formed in the upper plate may beconcave toward the inside of the core plate.

The lower plate 2440 may be made of a transparent material. The lowerplate 2440 may be insulative. The lower plate 2440 may be made of aglass material. The lower plate 2440 may have an antireflection coatingsurface. The lower plate 2440 may cover the upper portion of the cavity2431, a description of which will follow. Consequently, the lower plate2440 may be referred to as a cover glass. An insulation layer b may beformed on the lower plate 2440. The portion of the upper surface of thelower plate 2440 opposite to the cavity 2431 may be coated with theinsulation layer b. A fifth lower recess 2445 may be located in thecenter of the lower surface of the lower plate 2440. The fifth lowerrecess 2445 in the lower plate 2440 may be coated with the insulationlayer b. As a result, the second liquid L2 in the fifth lower recess2445 does not abut the fifth to eighth electrodes a5, a6, a7, and a8.

The lower plate 2440 may be provided at the corners thereof with a firstlower recess 2441, a second lower recess 2442, a third lower recess2443, and a fourth lower recess 2444, which are arranged in thecounterclockwise direction. The corners of the lower plate 2440 may becut inward to form the first lower recess 2441, the second lower recess2442, the third lower recess 2443, and the fourth lower recess 2444 inthe counterclockwise direction. The first to fourth lower recesses 2441,2442, 2443, and 2444 may be located between the first to fourth lowercorners 2451, 2452, 2453, and 2454 and the fifth to eighth electrodesa5, a6, a7, and a8. The first to fourth lower corners 2451, 2452, 2453,and 2454 may be connected to the fifth to eighth electrodes a5, a6, a7,and a8 via the first to fourth lower recesses 2441, 2442, 2443, and2444. The first to fourth lower corners 2451, 2452, 2453, and 2454 maybe connected to the fifth to eighth electrodes a5, a6, a7, and a8 vialower conduction portions (not shown) extending through the first tofourth lower recesses 2441, 2442, 2443, and 2444. In this case, each ofthe lower conduction portions may be conductive epoxy.

The lower board 2450 may be the lowermost portion of the liquid lens2400. The lower plate 2440 may be located on the lower board 2450. Thelower surface of the lower board 2450 may abut the lower inner wall ofthe second lens receiving hole 2230. The lower board 2450 may beconnected to the core plate 2430. The lower board 2450 may be connectedto the main board 2700. The lower board 2450 may supply power to thefifth to eighth electrodes a5, a6, a7, and a8 of the core plate 2430, adescription of which will follow, under the control of the main board2700. The lower board 2450 may change the direction, intensity, andwavelength of the current that is supplied to the fifth to eighthelectrodes a5, a6, a7, and a8 and the position to which the current issupplied.

The lower board 2450 may include a lower circuit board 2450 a and alower connection board 2450 b.

The lower circuit board 2450 a may be a printed circuit board (PCB). Thelower circuit board 2450 a may be formed in the shape of a plate. Thelower circuit board 2450 a may be formed in the shape of a quadrangularplate.

The lower circuit board 2450 a may be provided at the portion thereofcorresponding to (opposite to) the cavity 2431, a description of whichwill follow, or the portion thereof radially extending from the portionthereof corresponding to (opposite to) the cavity 2431 with a lowerguide hole 2445. Consequently, the upper surface of the uppermost lensof the second lens unit 2500 may be fixed by the lower guide hole 2445in the state of abutting the lower plate 2440. That is, the uppermostlens of the second lens unit 2500 may not be fixed in the state ofabutting the lower circuit board 2450 a, which is important from theaspect of electrical control and which may be worn or separated due tofriction, but may be fixed in the state of abutting the lower plate2440.

The lower circuit board 2450 a may be provided with a first lower corner2451, a second lower corner 2452, a third lower corner 2453, and afourth lower corner 2454, which are arranged in the counterclockwisedirection. The first to fourth lower corners 2451, 2452, 2453, and 2454may be located further inward than the corners of the core plate 2430.That is, the corners of the lower board 2450 may be located inward fromthe corners of the core plate 2430. When the liquid lens 2400 isinserted, therefore, the friction between the first to fourth lowercorners 2451, 2452, 2453, and 2454 and the lower inner wall and the sidewall of the third lens receiving hole 2240 may be minimized. As aresult, the first to fourth lower corners 2451, 2452, 2453, and 2454 maybe inhibited from being separated from the core plate 2430, whereby thelower circuit board 2450 a may be inhibited from being separated fromthe core plate 2430.

The first to fourth lower corners 2451, 2452, 2453, and 2454 may beconnected to the core plate 2430. The first to fourth lower corners2451, 2452, 2453, and 2454 may be connected to the electrode unit a ofthe core plate 2430 corresponding thereto (opposite thereto). The firstlower corner 2451 may be connected to the fifth electrode a5. The secondlower corner 2452 may be connected to the sixth electrode a6. The thirdlower corner 2453 may be connected to the seventh electrode a7. Thefourth lower corner 2454 may be connected to the eighth electrode a8.The first to fourth lower corners 2451, 2452, 2453, and 2454 may beconnected to the fifth to eighth electrodes a5, a6, a7, and a8 via fourlower conduction portions (not shown). In this case, the lowerconduction portions (not shown) may extend through the first to fourthlower recesses 2441, 2442, 2443, and 2444 corresponding to (opposite to)the first to fourth lower corners 2451, 2452, 2453, and 2454, adescription of which will follow. In addition, each of the lowerconduction portions may be conductive epoxy. As a result, the first tofourth lower corners 2451, 2452, 2453, and 2454 may be adhered to thefifth to eighth electrodes a5, a6, a7, and a8 via the conductive epoxy.In addition, the first to fourth lower corners 2451, 2452, 2453, and2454 may be adhered to the fifth to eighth electrodes a5, a6, a7, and a8via electrode pads.

The lower connection board 2450 b may be a flexible printed circuitboard (FPCB). The lower connection board 2450 b may be connected to thelower circuit board 2450 a. The lower connection board 2450 b may beconnected to the main board 2700. As a result, the main board 2700 maysupply power to the fifth to eighth electrodes a5, a6, a7, and a8 viathe lower connection board 2450 b and the lower circuit board 2450 a.

The lower connection board 2450 b may extend downward from the otherside of the lower circuit board 2450 a. The other side may be a sidelocated at the end in the direction in which the liquid lens 2400 isinserted through the insertion hole 2232. The junction between the lowerconnection board 2450 b and the lower circuit board 2450 a may be round.The lower connection board 2450 b may be received in the board receivingrecess 2234, and may extend downward. In this case, the lower connectionboard may be protected from the outside, since the cover member 2100 islocated outside the lower connection board.

Hereinafter, various examples of the liquid lens 2400 according to thefirst embodiment will be described with reference to FIGS. 23A through23L. In the following description, light reflected by a subject istransmitted through the liquid lens 2400 from top to bottom. Inaddition, an upper board 2410 and a lower board 2450 having the sametechnical concept as in the above description will be omitted fromvarious examples of the liquid lens 2400, and a description thereof willbe omitted.

In the liquid lens 2400 of FIG. 23A, the fifth upper recess 2425 may beformed in the upper plate 2420, and the fifth lower recess 2445 may beformed in the lower plate 2440. The electrode unit a is disposed on theinner wall of the cavity 2431 and the upper surface and the lowersurface of the core plate 2430. The upper electrode unit a1, a2, a3, anda4 may be disposed on the upper surface of the core plate 2430, and maybe interrupted at the circumference of the cavity 2431 on the uppersurface of the core plate 2430. The inner wall electrode unit a5, a6,a7, and a8 may be disposed on the upper surface of the core plate 2430at the circumference of the cavity 2431, the inner wall of the cavity2431, and the lower surface of the core plate 2430, and may beinterrupted at the circumference of the cavity 2431 on the upper surfaceof the core plate 2430. That is, the upper electrode unit a1, a2, a3,and a4 and the inner wall electrode unit a5, a6, a7, and a8 may beinterrupted on the upper surface of the core plate 2430, and thus maynot be connected to each other. The insulation layer b may be disposedon the electrode unit a along the circumference of the cavity 2431 inthe core plate 2430. In this case, the insulation layer b may extendthrough the gap between the upper electrode unit a1, a2, a3, and a4 andthe inner wall electrode unit a5, a6, a7, and a8. In addition, theinsulation layer b may be disposed on the upper surface of the fifthlower recess 2445. As a result, the lower surface of the insulationlayer b may be disposed in the fifth lower recess 2445. The insulationlayer b may extend from the lower surface thereof along the inner wallof the cavity 2431 so as to be disposed on the inner wall electrode unita5, a6, a7, and a8. The insulation layer b may extend through the innerwall electrode unit a5, a6, a7, and a8 from the inner wall of the cavity2431 along the upper surface of the core plate 2430 so as to be locatedon the upper electrode unit a1, a2, a3, and a4. The second liquid L2 maybe disposed in the lower portion of the cavity 2431 so as to be receivedin the lower portion of the insulation layer b. The first liquid L1 maybe disposed in the upper portion of the cavity 2431 so as to be receivedin the upper portion of the insulation layer b and the fifth upperrecess 2425. In this case, the first liquid L1 may abut the upperelectrode unit a1, a2, a3, and a4.

The first liquid L1 may be a conductive liquid, and the second liquid L2may be a nonconductive liquid. The first liquid L1 may include water,and the second liquid L2 may include oil.

The first liquid L1 may be located on the second liquid L2. The firstliquid L1 and the second liquid L2 may have different indices ofrefraction, and may contact each other to form an interfacetherebetween. When voltage is applied to the electrode unit a, theinterface may move along the inner wall of the cavity 2431.

In the initial state, in which no voltage is applied to the electrodeunit a, the liquid lens 2400 may have a negative (−) diopter. Whenvoltage is applied to the electrode unit a, the liquid lens 2400 mayhave a positive (+) diopter. That is, in the initial state, theinterface may be convex downward. In this case, the liquid lens 2400 mayserve as a concave lens. As voltage is applied to the electrode unit a,the interface may gradually become convex upward, whereby the liquidlens 2400 may serve as a convex lens. In addition, the radius ofcurvature of the interface that is convex downward in the initial statemay be greater than the radius of curvature of the interface that isconvex upward in the state in which the maximum voltage is applied tothe electrode unit a.

The liquid lens 2400 of FIG. 23A may be analogous with the liquid lens2400 of FIG. 23B. Compared with the liquid lens 2400 of FIG. 23A,however, the fifth lower recess 2445 is omitted. As a result, theinsulation layer b may be directly disposed on the upper surface of thelower plate 2440 opposite to the cavity 2431.

The liquid lens 2400 of FIG. 23A may be analogous with the liquid lens2400 of FIG. 23C. Compared with the liquid lens 2400 of FIG. 23A,however, the fifth lower recess 2445 is omitted. Furthermore, noinsulation layer b may be disposed on the lower plate 2440.

The liquid lens 2400 of FIG. 23A may be analogous with the liquid lens2400 of FIG. 23D. However, the cavity 2431 may be inclined. In thiscase, the width of the cavity 2431 may gradually decrease downward. Thatis, the horizontal sectional area of the cavity 2431 may graduallydecrease downward. Furthermore, the liquid lens 2400 of FIG. 23E isconfigured such that the cavity 2431 in the liquid lens 2400 of FIG. 23Bis inclined, and the liquid lens 2400 of FIG. 23F is configured suchthat the cavity 2431 in the liquid lens 2400 of FIG. 23C is inclined.

The liquid lens 2400 of FIG. 23A may be analogous with the liquid lens2400 of FIG. 23G. However, no fifth upper recess 2425 is formed in theliquid lens 2400 of FIG. 23H. Instead, the upper plate 2420 and the coreplate 2430 may be coupled to each other using a first adhesive member2427 and a second adhesive member 2428. That is, the upper plate 2420and the core plate 2430 may be spaced apart from each other by the firstadhesive member 2427 and the second adhesive member 2428. The gapbetween the upper plate and the core plate may be filled with the secondliquid L2, which may abut the upper electrodes a1, a2, a3, and a4. Inthis case, each of the first adhesive member 2427 and the secondadhesive member 2428 may be a nonconductive material. The liquid lens2400 of FIG. 23H is configured such that the first and second adhesivemembers 2427 and 2428 are disposed in place of the upper recess 2425 inthe liquid lens 2400 of FIG. 23B. The liquid lens 2400 of FIG. 23I isconfigured such that the first and second adhesive members 2427 and 2428are disposed in place of the upper recess 2425 in the liquid lens 2400of FIG. 23C. The liquid lens 2400 of FIG. 23J is configured such thatthe first and second adhesive members 2427 and 2428 are disposed inplace of the upper recess 2425 in the liquid lens 2400 of FIG. 23D. Theliquid lens 2400 of FIG. 23K is configured such that the first andsecond adhesive members 2427 and 2428 are disposed in place of the upperrecess 2425 in the liquid lens 2400 of FIG. 23E. The liquid lens 2400 ofFIG. 23L is configured such that the first and second adhesive members2427 and 2428 are disposed in place of the fifth upper recess 2425 inthe liquid lens 2400 of FIG. 23F.

Gaps 2429 shown in FIGS. 23A to 23L mean that upper electrodes and innerwall electrodes that are adjacent to each other (e.g. a2/a3 and a6/a7)are separated from each other. In an embodiment, the gaps 2429 may befilled with the insulation layer b through the process of disposing theinsulation layer b. As a result, the adjacent electrodes may be moresecurely separated from each other. In another embodiment, the gaps 2429may be realized as empty spaces in the case in which the insulationlayer b is made of an insulation film.

The liquid lens 2400 according to the first embodiment may be disposedin the lens module in the inverted state (see FIG. 24). In this case,the liquid lens 2400 may have a positive (+) diopter in the initialstate, in which no voltage is applied to the electrode unit a, and theliquid lens 2400 may have a negative (−) diopter when voltage is appliedto the electrode unit a. That is, in the initial state, the interfacemay be convex upward. In this case, the liquid lens 2400 may serve as aconvex lens. As voltage is applied to the electrode unit a, theinterface may gradually become convex downward, whereby the liquid lens2400 may serve as a concave lens. In addition, the radius of curvatureof the interface that is convex upward in the initial state may begreater than the radius of curvature of the interface that is convexdownward in the state in which the maximum voltage is applied to theelectrode unit a.

The second lens unit 2500 may include one or more lenses. The secondlens unit 2500 may include three lenses. The lenses of the second lensunit 2500 may be located in the state of being stacked. The second lensunit 2500 may be received in the second lens receiving hole 2240. Thelenses of the second lens unit 2500 may be configured such that theupper portion of each lens abuts the stair of the second lens receivinghole 2240 or an O-ring and such that the lower portion of each lens issupported and fixed by the lower lens or an O-ring. The upper portion ofthe uppermost lens of the second lens unit 2500 may be fixed in thestate of abutting the lower surface of the lower plate 2440 of theliquid lens 2400,

The infrared filter 2600 may inhibit infrared light from being incidenton the image sensor. The infrared filter 2600 may be located between thelens module and the main board 2700. The infrared filter 2600 may belocated between the lens module and the image sensor. The infraredfilter 2600 may be made of a film material or a glass material. Theinfrared filter 2600 may be formed by coating a plate-shaped opticalfilter, such as a cover glass for protecting an image plane, withinfrared cutoff material. The infrared filter 2600 may be an infraredcutoff filter or an infrared absorption filter.

The main board 2700 may be a printed circuit board (PCB). The main board2700 may support the lens holder 2200. The image sensor may be mountedon the main board 2700. In an example, the image sensor may be locatedat the inside of the upper surface of the main board 2700, and the lensholder 2200 may be located at the outside of the upper surface of themain board 2700. In this structure, light that has passed through thelens module may be radiated to the image sensor mounted on the mainboard 2700. The main board 2700 may supply power to the liquid lens2400. The main board 2700 may supply power to the first to fourthelectrodes a1, a2, a3, and a4 via the upper plate 2410. The main board2700 may supply power to the fifth to eighth electrodes a5, a6, a7, anda8 via the lower plate 2450. Meanwhile, the controller may be located atthe main board 2700. Consequently, the direction, intensity, andwavelength of current that is supplied to the first to eighth electrodesa1, a2, a3, a4, a5, a6, a7, and a8 and the position to which the currentis supplied may be controlled.

The image sensor may be mounted on the main board 2700. The image sensormay be located such that the optical axis of the image sensor is alignedwith the optical axis of the lens module. As a result, the image sensormay acquire light that has passed through the lens module. The imagesensor may output radiated light as an image. The image sensor may be acharge coupled device (CCD), metal oxide semiconductor (MOS), CPD, orCID. However, the kind of image sensor is not limited thereto.

The controller may be mounted on the main board 2700. The controller maycontrol the direction, intensity, and wavelength of current that issupplied to the first to eighth electrodes a1, a2, a3, a4, a5, a6, a7,and a8. The controller may control the liquid lens 2400 to perform atleast one of the AF and OIS functions of the camera module 2000. Thatis, the controller may control the liquid lens 2400 to change thecurvature of the interface of the liquid lens 2400.

As shown in FIG. 21, the lower board 2450 may receive a single controlsignal from the controller via a lower connection board 2450 b includinga single pad, and the fifth to eighth electrodes a5, a6, a7, and a8 maybe connected to each other so as to receive the single control signal.That is, the fifth to eighth electrodes a5, a6, a7, and a8 mayconstitute a common electrode.

In addition, the upper board 2410 may receive four control signals fromthe controller via a upper connection board 2410 b including four pads,and each of the first to fourth electrodes a1, a2, a3, and a4 mayreceive a corresponding one of the four control signals. That is, thefirst to fourth electrodes a1, a2, a3, and a4 may constitute fourindividual electrodes.

In another embodiment, the upper board may include a single pad, and thelower board may include four pads. Other elements may also be modifiedin response thereto.

Hereinafter, the structure of a camera module 2001 according to a secondembodiment will be described with reference to the drawings. FIG. 25 isan exploded perspective view showing a camera module according to asecond embodiment, FIG. 26 is an exploded perspective view showing aliquid lens according to a second embodiment, and FIG. 27 is a sectionalview showing the camera module according to the second embodiment.

The structure of the camera module 2000 according to the firstembodiment may be analogous with the structure of the camera module 2001according to the second embodiment. The structure of the liquid lens2400 of the camera module 2000 according to the first embodiment may beanalogous with the structure of the liquid lens 2400 according to thesecond embodiment except for the upper and lower boards 2410 and 2450.Hereinafter, the structure of the upper and lower boards 2410 and 2450of the second embodiment will be described based on the technicalfeatures thereof that are different from those of the upper and lowerboards 2410 and 2450 of the first embodiment.

The liquid lens 2400 may be configured such that boards and plates arestacked. The liquid lens 2400 may include an upper board 2410, an upperplate 2420, a core plate 2430, a lower plate 2440, and a lower board2450.

The upper board 2410 may include an upper circuit board 2410 a, and theupper board 2410 and the lower board 2450 may be connected to each othervia a first upper and lower connection board 2410 c and a second upperand lower connection board 2410 d. Unlike the upper board 2410 of thefirst embodiment, the upper connection board 2410 b may be omitted. Thereason for this is that the upper board may be connected to the mainboard 2700 via a lower connection board 2450 b of the lower board 2450.In a modification (not shown), the upper board may include an upperconnection board, and the lower connection board of the lower board maybe omitted. In this case, therefore, the lower board may be connected tothe main board 2700 via the upper connection board of the upper board.That is, in the case in which the first upper and lower connection board2410 c and/or the second upper and lower connection board 2410 d isprovided, as illustrated in the second embodiment and the modificationthereof, any one selected from between the upper connection board andthe lower connection board may be omitted. Furthermore, in the case inwhich the upper board 2410 and the lower board 2450 are integrallyconnected to each other, as in the second embodiment, the coatingstructure of the electrode unit a is simplified.

The upper circuit board 2410 a may be a printed circuit board (PCB). Theupper circuit board 2410 a may be formed in the shape of a plate. Theupper circuit board 2410 a may be formed in the shape of a quadrangularplate.

The upper circuit board 2410 a may be provided at the portion thereofcorresponding to (opposite to) a cavity 2431, a description of whichwill follow, or the portion thereof radially extending from the portionthereof corresponding to (opposite to) the cavity 2431 with an upperguide hole 2415. Unlike the upper circuit board 2410 a of the firstembodiment, the upper guide hole 2415 may not extend to one side. Whenthe liquid lens 2400 is inserted, therefore, the first upper and lowerconnection board 2410 c and the second upper and lower connection board2410 d are introduced first, whereby the upper circuit board 2410 a maybe inhibited from being worn or from being separated from the upperplate 2420 or the core plate 2430.

Unlike the first to fourth upper corners 2411, 2412, 2413, and 2414 ofthe first embodiment, the first to fourth upper corners 2411, 2412,2413, and 2414 of the upper circuit board 2410 a may not be locatedfurther inward than the corners of the core plate. When the liquid lens2400 is inserted, therefore, the first upper and lower connection board2410 c and the second upper and lower connection board 2410 d areintroduced first, with the result that the first to fourth upper corners2411, 2412, 2413, and 2414 may be inhibited from being separated fromthe core plate 2430, whereby the upper circuit board 2410 a may beinhibited from being separated from the core plate 2430.

Each of the first and second upper and lower connection boards 2410 cand 2410 d may be a flexible printed circuit board (FPCB). The first andsecond upper and lower connection boards 2410 c and 2410 d may connectthe upper circuit board 2410 a to a lower circuit board 2450 a. As aresult, the main board 2700 may supply power to the first to fourthelectrodes a1, a2, a3, and a4 via the lower circuit board 2450 a, thefirst and second upper and lower connection boards 2410 c and 2410 d,and the upper circuit board 2410 a.

The first and second upper and lower connection boards 2410 c and 2410 dmay be spaced apart from each other. The first and second upper andlower connection boards 2410 c and 2410 d may be turned up at one sideof the upper circuit board 2410 a so as to be connected to one side ofthe lower circuit board 2450 a. That is, the first and second upper andlower connection boards 2410 c and 2410 d may be curved. In this case,one side may be a side located at the entrance in the direction in whichthe liquid lens 2400 is inserted through the insertion hole 2232.

The lower board 2450 may include a lower circuit board 2450 a and alower connection board 2450 b. The upper board 2410 and the lower board2450 may be connected to each other via the first upper and lowerconnection board 2410 c and the second upper and lower connection board2410 d. For the same reason as the upper board 2410, first to fourthlower corners 2451, 2452, 2453, and 2454 of the lower board 2450 may notbe located further inward than corners of the core plate 2230, unlikethe first to fourth lower corners 2451, 2452, 2453, and 2454 of thefirst embodiment.

Hereinafter, the AF and OIS functions of the camera module 2000 or 2001according to the first or second embodiment will be described. Thefunctions of the camera module 2000 or 2001 according to the first orsecond embodiment may be performed by changing the curvature of theinterface between the conductive liquid L1 and the nonconductive liquidL2 received in the cavity 2431.

The conductive liquid L1 may be located in the upper portion of thecavity 2431. The conductive liquid L1 may be received in the upperportion of the cavity 2431 in the state of abutting the upper recess2425, the first to fourth electrodes a1, a2, a3, and a4, the insulationlayer b, and the nonconductive liquid L2. The conductive liquid L1 maybe polar. For example, the conductive liquid L1 may be water.

The nonconductive liquid L2 may be located in the lower portion of thecavity 2431. The nonconductive liquid L2 may be received in the lowerportion of the cavity 2431 in the state of abutting the insulation layerb and the conductive liquid L1. The nonconductive liquid L2 may benonpolar. For example, the nonconductive liquid L2 may be oil. Thenonconductive liquid L2 may be silicone.

The specific gravities of the conductive liquid L1 and the nonconductiveliquid L2 may be similar or almost equal to each other. In a system inwhich the conductive liquid L1 and the nonconductive liquid L2 coexist,therefore, gravity may be ignored. That is, the system in which theconductive liquid L1 and the nonconductive liquid L2 exist is littleaffected by gravity but is greatly affected by surface tension.

The interface between the conductive liquid L1 and the nonconductiveliquid L2 may be changed. More specifically, the curvature of theinterface between the conductive liquid L1 and the nonconductive liquidL2 may be controlled to perform the AF and OIS functions.

An example of the AF function will be described. When voltage is appliedsuch that the first to fourth electrodes a1, a2, a3, and a4, located atthe upper portion of the cavity 2431, and the fifth to eighth electrodesa5, a6, a7, and a8, located at the lower portion of the cavity 2431,have different polarities, the conductive liquid L1, located in theupper portion of the cavity 2431, abuts the first to fourth electrodesa1, a2, a3, and a4 and is separated from the fifth to eighth electrodesa5, a6, a7, and a8 by the insulation layer b and the nonconductiveliquid L2, whereby an electrowetting phenomenon occurs. Consequently,the curvature of the interface is changed depending on the magnitude ofvoltage, whereby the AF function is performed. The magnitude of voltagemay be controlled by the controller, as previously described.

An example of the OIS function will be described. When voltage isapplied such that some of the first to fourth electrodes a1, a2, a3, anda4, located at the upper portion of the cavity 2431, and the fifth toeighth electrodes a5, a6, a7, and a8, located at the lower portion ofthe cavity 2431, have different polarities, the curvature of theinterface may be changed so as to be biased to one of the first tofourth electrodes a1, a2, a3, and a4. Consequently, the magnitude ofvoltage and some of the first to fourth electrodes a1, a2, a3, and a4 towhich voltage is to be applied may be selected to perform the OISfunction. The magnitude of voltage and the electrodes to which voltageis to be applied may be controlled by the controller, as previouslydescribed.

In a modification (not shown), the nonconductive liquid may be locatedin the upper portion of the cavity, and the conductive liquid may belocated in the lower portion of the cavity. In this case, the insulationlayer may be located in a reverse state. That is, a circular insulationlayer may be coated on a portion of the upper recess, and a circularinsulation layer may be coated on the lower surface of the core platealong the circumference of the cavity. In addition, no circularinsulation layer may be coated on a portion of the lower recess, and nocircular insulation layer may be coated on the upper surface of the coreplate along the circumference of the cavity. In this structure, theoperation of the first or second embodiment is reversely carried out toperform the AF and OIS functions.

Hereinafter, a method of manufacturing the lens module according to thefirst or second embodiment will be described with reference to thedrawings. FIG. 28 is a conceptual view showing a method of manufacturingthe lens module according to the first embodiment, FIG. 29 is aconceptual view showing a method of manufacturing the lens moduleaccording to the second embodiment, and FIG. 30 is a flowchart showingthe method of manufacturing the lens module according to the first orsecond embodiment.

The method of manufacturing the lens module according to the first orsecond embodiment may include a first step (S1) of molding the lensholder 2200, a second step (S2) of inserting the first lens unit 2300, athird step (S3) of inserting the liquid lens 2400 through the insertionhole 2232, and a fourth step (S4) of inserting the second lens unit2500.

The first step (S1) is a step of molding the lens holder 2200. The lensholder 2200 may be formed by plastic injection. The lens holder 2200 maybe manufactured through a process of injecting molten plastic into amain mold (not shown) having a hole mold (not shown) corresponding tothe hole 2210 and the insertion hole 2232 and solidifying the plastic.

The second step (S2) is a step of inserting the first lens unit 2300.The first lens unit 2300 may be inserted from bottom to top through thelower opening of the hole 2210 (in the direction indicated by arrow A).The first lens unit 2300 may be inserted into the hole 2210, and may bereceived and fixed in the first lens receiving hole 2220.

The third step (S3) is a step of inserting the liquid lens 2400. Theliquid lens 2400 may be laterally inserted through the insertion hole2232 (in the direction indicated by arrow B). The inwardly inclinedportion 2310 may be formed along the outer circumference of the lowersurface of the lowermost lens of the first lens unit 2300. As a result,the friction between the first lens unit and the upper plate 2420 may bereduced when the liquid lens 2400 is inserted. Furthermore, the first tofourth upper corners 2411, 2412, 2413, and 2414 and the first to fourthlower corners 2451, 2452, 2453, and 2454 of the liquid lens 2400according to the first embodiment may be formed inward, and the upperguide hole 2415 may be formed in the upper board 2410 in the directionin which the liquid lens 2400 is inserted (in the direction indicated byarrow B). As a result, the first to fourth upper corners 2411, 2412,2413, and 2414 and the first to fourth lower corners 2451, 2452, 2453,and 2454 may be inhibited from being separated from the core plate 2430when the liquid lens 2400 is inserted, whereby the upper circuit board2410 a may be inhibited from being separated from the core plate. Theliquid lens 2400 may be inserted into the hole 2210 through theinsertion hole 2232, and may be received and fixed in the second lensreceiving hole 2230. In addition, the liquid lens 2400 according to thesecond embodiment may have the first upper and lower connection board2410 c and the second upper and lower connection board 2410 d in thedirection in which the liquid lens is inserted (in the directionindicated by arrow B). Consequently, the same effect as the liquid lens2400 according to the first embodiment may be obtained. The liquid lens2400 may be inserted into the hole 2210 through the insertion hole 2232,and may be received and fixed in the second lens receiving hole 2230.

The fourth step (S4) is a step of inserting the second lens unit 2500.The second lens unit 2500 may be inserted from bottom to top through thelower opening of the hole 2210 (in the direction indicated by arrow C).The second lens unit 2500 may be inserted into the hole 2210, and may bereceived and fixed in the third lens receiving hole 2240.

In the method of manufacturing the lens module according to the first orsecond embodiment, the liquid lens 2400 may be inserted laterally. As aresult, all of the first lens unit 2300, the liquid lens 2400, and thesecond lens unit 2500 may be received in the hole 2210, which is formedthrough a single process (first step) (S1). Consequently, the opticalaxes of the first lens unit 2300, the liquid lens 2400, and the secondlens unit 2500 may be aligned with one another.

The core plate 2430, the upper plate 2420, and the lower plate 2440,described with reference to FIGS. 15 to 30, may also be defined as afirst plate, a second plate, and a third plate, respectively.

FIG. 31 is a view showing an embodiment of the camera module. The cameramodule may include a lens assembly 3000 and a control circuit 3999.

The lens assembly 3000 may include a liquid lens and/or a solid lens.The liquid lens may include a liquid, a plate, and an electrode. Theliquid may include a conductive liquid and a nonconductive liquid. Theelectrode may be disposed on or under the plate. In addition, theelectrode may include a common terminal and a plurality of individualterminals. A common terminal may be provided, and a plurality ofindividual terminals may be provided. The plate may include a firstplate having a cavity in which the liquid is located. The plate mayfurther include a second plate disposed on or under the first plate. Inaddition, the liquid lens may further include a third plate. The firstplate may be disposed between the second plate and the third plate. Theshape of the interface between the conductive liquid and thenonconductive liquid may be changed in response to a driving voltageapplied between the common terminal and the individual terminals,whereby the focal distance may be changed. The control circuit 3999 maysupply the driving voltage to the liquid lens, and may be disposed at asensor board having an image sensor. The camera module may furtherinclude a connector 3001. The connector 3001 may be connected to thecontrol circuit 3999 via a connection portion 3501, and the controlcircuit 3999 may be connected to an external power supply or anotherdevice.

The structure of the control circuit 3999 may be differently designeddepending on the specification of an imaging device. Particularly, inorder to reduce the magnitude of an operating voltage that is applied tothe lens assembly 3000, the control circuit 3999 may be realized by asingle chip. As a result, the size of a camera device mounted in aportable device may be further reduced.

The lens assembly 3000 may include a first lens unit 3100, a second lensunit 3400, a liquid lens 3300, a holder 3500, and a cover 3600. One ofthe first lens unit 3100 and the second lens unit 3400 may be omitted.

The structure of the lens assembly 3000 that is shown is merely anexample, and the structure of the lens assembly 3000 may be changeddepending on the specification of the camera device.

The first lens unit 3100 may be a region which is disposed in front ofthe lens assembly 3000 and on which light is incident from outside thelens assembly 3000. The first lens unit 3100 may be constituted by atleast one lens. Alternatively, two or more lenses may be aligned alongthe central axis to constitute an optical system. Here, the central axismay be the same as the optical axis of the optical system.

The first lens unit 3100 may include two lenses. However, the disclosureis not limited thereto.

The upper portion and the lower portion of the holder 3500 may be opensuch that a through-hole is formed in the holder. The first lens unit3100, the second lens unit 3400, and the liquid lens 3300 may be mountedin the through-hole formed in the holder 3500. The first and second lensunit 3100 and 3400 may be referred to as first and second solid lensunits so as to be distinguished from the liquid lens 3300. Specifically,the first lens unit 3100 may be disposed in the upper portion of theholder 3500, and the second lens unit 3400 may be disposed and coupledin the lower portion of the holder 3500.

An exposure lens (not shown) may be provided at the front of the firstlens unit 3100. A cover glass may be disposed in front of the exposurelens. Since the exposure lens protrudes to the outside and thus isexposed to the outside, the surface of the lens may be damaged. In thecase in which the surface of the lens is damaged, the quality of imagestaken by the camera module may be deteriorated. In order to inhibit orrestrain damage to the surface of the exposure lens, the cover glass maybe disposed, a coating layer may be formed, or the exposure lens may bemade of a wear-resistant material for inhibiting damage to the surfaceof the exposure lens.

The second lens unit 3400 may be disposed at the rear of the first lensunit 3100 and the liquid lens 3300. Light incident on the first lensunit 3100 from the outside may pass through the liquid lens 3300 and maybe incident on the second lens unit 3400. The second lens unit 3400 maybe disposed in the through-hole formed in the holder 3500 so as to bespaced apart from the first lens unit 3100.

The liquid lens 3300 may be disposed under the first lens unit 3100, andthe second lens unit 3400 may be disposed under the liquid lens 3300.The second lens unit 3400 may be constituted by at least one lens.Alternatively, two or more lenses may be aligned along the central axisto constitute an optical system.

The liquid lens 3300 may be disposed between the first lens unit 3100and the second lens unit 3400. The structure of the liquid lens 3300will be described below with reference to FIGS. 32A and 32B.

The liquid lens 3300, the first lens unit 3100, disposed on the liquidlens, and the second lens unit 3400, disposed under the liquid lens, maybe disposed and fixed in the holder 3500. The liquid lens 3300 may alsobe aligned along the central axis in the same manner as the first lensunit 3100 and the second lens unit 3400.

First and second connection electrodes 3356 and 3346 (see FIG. 32B) ofthe liquid lens 3300 may be connected to a pad 3385 of a connectionboard 3380 exposed outside the holder 3500. For example, the connectionboard 3380 may be a flexible printed circuit board, and the pad 3385 maybe connected to a pad 3810 of a circuit board 3800 disposed under thepad 3385.

The pads 3385 and 3810 may be terminals exposed from the connectionboard 3380 and the circuit board 3800, respectively.

Although not shown, conductive epoxy may be disposed between a firstelectrode 3355 and the first connection electrode 3356. In addition,conductive epoxy may be disposed between a second electrode 3345 and thesecond connection electrode 3346.

The first and second connection electrodes 3356 and 3346 may be disposedat the connection board 3380. The connection board 3380 may include aplurality of upper terminals and a plurality of lower terminals. Theupper terminals may be connected to the first and second electrodes 3355and 3345. The upper terminals may correspond to the first connectionelectrode 3356. The lower terminals may be connected to terminals of thesensor board. For example, the lower terminals may correspond to the pad3385, and the terminals of the sensor board may correspond to the pad3810 of the circuit board 3800.

The cover 3600 may be disposed so as to surround the first lens 3100,the second lens 3400, the liquid lens 3300, and the holder 3500. Thecover 3600 and the holder 3500 may be disposed on a base 3700. The base3700 may be omitted.

The circuit board 3800 may be disposed under the base 3700, and the pad3810 may supply current to the first and second electrodes 3355 and 3345(see FIGS. 32A and 32B) of the liquid lens 3300.

In addition, although not shown, a light receiving element, such as animage sensor, may be disposed under the second lens unit 3400. The lightreceiving element may be provided in the sensor board together with thecircuit board 3800. The horizontal and/or vertical length of a unitpixel of an image sensor 3900 may be, for example, 2 micrometers (μm) orless.

FIGS. 32A and 32B are views showing the liquid lens of the camera moduleof FIG. 31.

The liquid lens 3300 may include a first plate 3310 having therein acavity for receiving a first conductive liquid 3350 and a secondnonconductive liquid 3340, a first electrode 3355 disposed on the firstplate 3310, a second electrode 3345 disposed under the first plate, asecond plate 3320 disposed on the first electrode 3355, and a thirdplate 3330 disposed under the second electrode 3345.

The first plate 3310 may be disposed between the second plate 3320 andthe third plate 3330, and may include upper and lower openings having apredetermined inclined surface (e.g. an inclined surface having an angleof about 59 to 61 degrees). A region defined by the inclined surface,the opening contacting the second plate 3320, and the opening contactingthe third plate 3330 may be referred to as a ‘cavity.’

The first plate 3310 is a structure for receiving the first and secondliquids 3350 and 3340. The second plate 3320 and the third plate 3330include regions through which light passes. The second plate 3320 andthe third plate 3330 may be made of a light transmissive material suchas glass. For the convenience in processing, the second plate 3320 andthe third plate 3330 may be made of the same material.

In addition, the first plate 3310 may include impurities, which makelight transmission difficult.

The second plate 3320 is a region on which light from the first lensunit 3100 is incident in order to be guided to the cavity, and the thirdplate 3330 is a region through which the light having passed through thecavity passes in order to be guided to the second lens unit 3400.

The cavity may be filled with the first liquid 3350 and the secondliquid 3340, which exhibit different properties. An interface may beformed between the first liquid 3350 and the second liquid 3340. Thecurvature and inclination of the interface between the first liquid 3350and the second liquid 3340 may be changed.

That is, in the case in which the surface tension of the first andsecond liquids 3350 and 3340 is changed using electricity, the size ofthe camera device is smaller than in the case in which the solid lensesare moved (the distance between the lenses is adjusted) to adjust thefocal distance, and power consumption is lower than in the case in whichthe lenses are mechanically moved using a motor.

The second liquid 3340 may be a nonconductive liquid, such asphenyl-based silicone oil.

The first liquid 3350 may be a conductive liquid, such as a mixture ofethylene glycol and sodium bromide (NaBr).

Each of the first liquid 3350 and the second liquid 3340 may include atleast one selected from between a disinfectant and an antioxidant. Theantioxidant may be a phenyl-based antioxidant or a phosphorus (P)-basedantioxidant. The disinfectant may be any one selected from amongalcohol-based, aldehyde-based, and phenyl-based disinfectants.

The first electrode 3355 may be disposed on a portion of the uppersurface of the first plate 3310, and may directly contact the firstliquid 3350. The second electrode 3345 may be spaced apart from thefirst electrode 3355, and may be disposed on the upper surface, the sidesurface, and the lower surface of the first plate 3310.

The side surface of the first plate 3310 or the side surface of aninsulation layer 3360 may constitute the inclined surface or thesidewall of the cavity. The first electrode 3355 may contact the firstliquid 3350 and the second liquid 3340 in the state in which theinsulation layer 3360, a description of which will follow, is disposedtherebetween.

An electrical signal from an external circuit board may be applied tothe first electrode 3355 and the second electrode 3345 in order tocontrol the interface between the first liquid 3350 and the secondliquid 3340.

Each of the first electrode 3355 and the second electrode 3345 may bemade of a conductive material. For example, each of the first electrodeand the second electrode may be made of a metal, such as chrome (Cr).Chromium or chrome is a glossy silver rigid transition metal, which isnot fragile, does not readily discolor, and has a high melting point.

Since an alloy including chromium exhibits high corrosion resistance andrigidity, chromium may be used in the state of being alloyed with adifferent metal. In particular, chrome (Cr) exhibits high resistance tothe conductive liquid in the cavity, since chrome is not easily corrodedor discolored.

The insulation layer 3360 may be disposed so as to cover the uppersurface of the third plate 3330 on the bottom surface of the cavity, thesecond electrode 3345 disposed on the sidewall of the cavity, a portionof the first electrode 3355 on the upper surface of the first plate3310, the first plate 3310, and the second electrode 3345. Theinsulation layer 3360 may be realized by, for example, a parylene Ccoating agent, and may further include a white dye. The white dye mayincrease the frequency at which light is reflected by the insulationlayer 3360 disposed on the sidewall i of the cavity.

As shown, the second liquid 3340 may be in surface contact with thethird plate 3330 in the state in which the insulation layer 3360 isdisposed therebetween, and the first liquid 3350 may be in directsurface contact with the second plate 3320.

The cavity may include a first opening facing the second plate 3320 anda second opening facing the third plate 3330. The size in section of thefirst opening may be greater than the size in section of the secondopening. In the case in which each opening has a circular section, thesize of each of the first and second openings may be the radius. In thecase in which each opening has a square section, the size of each of thefirst and second openings may be the length of one side.

The edge of each of the second plate 3320 and the third plate 3330 maybe quadrangular. However, the disclosure is not limited thereto.

The first electrode 3355 may be exposed on at least a portion of theedge of the second plate 3320, and the second electrode 3345 may beexposed on at least a portion of the edge of the third plate 3330.

The first connection electrode 3356 may be disposed on the firstelectrode 3355 at the outer region of the second plate 3320, and thesecond connection electrode 3346 may be disposed on the second electrode3345 at the outer region of the third plate 3330.

The first connection electrode 3356 and the second connection electrode3346 may be integrally formed with the first electrode 3355 and thesecond electrode 3345, respectively.

The first connection electrode 3356 and the second connection electrode3346 may be connected to the connection board 3380, which is a flexibleprinted circuit board, as previously described.

FIGS. 33 and 34 are sectional views showing the lens assembly of thecamera module of FIG. 31, and FIG. 35 is a view showing the structure ofthe lens assembly of the camera module of FIGS. 33 and 34, from whichthe liquid lens is removed. Hereinafter, the disposition of the firstlens unit 3100, the liquid lens 3300, and the second lens unit 3400 inthe lens assembly according to the embodiment will be described withreference to FIGS. 33 to 35.

First to third regions region1 to region3 may be provided in the holder3500. The first lens unit 3100 may be inserted into the first regionregion1, the liquid lens 3300 may be disposed in the second regionregion2, and the second lens unit 3400 may be disposed in the thirdregion region3. The first region region1 and the second region region2may be spaced apart from each other by a first gap gap1, and the secondregion region2 and the third region region3 may be spaced apart fromeach other by a second gap gap2. The first gap gap1 may be the distancebetween the first lens unit 3100 and the liquid lens 3300, and thesecond gap gap2 may be the distance between the liquid lens 3300 and thesecond lens unit 3400.

The through-hole formed in the holder 3500 may include the first tothird regions region1 to region3.

The holder 3500 may be disposed so as to surround the side surface andthe front surface of the first region region1. A portion of the holder3500 on the front surface of the first region facing the first lens unit3100 may be removed to form an opening.

The holder 3500 may be disposed so as to surround the side surfaces ofthe second region region2 and the third region region3.

In the lens assembly 3000 according to the embodiment, the holder 3500may be disposed so as to surround the through-hole formed therein.

FIG. 35 shows the state in which the first lens unit 3110 and 3120 andthe second lens unit 3410, 3420, and 3430 are disposed in the first andthird regions region1 and region3 in the holder 3500 and in which thesecond region region2 is empty.

The cover 3600 may be disposed so as to cover a portion of the sidesurface and the upper surface of the holder 3500. Openings formed inside surfaces of the holder 3500 for use as the entrances of the liquidlens 3300 may also be covered by the cover 3600.

The openings may be formed in two opposite side surfaces of the holder3500 so as to be used as the entrances for the liquid lens 3300. Theopenings may be respectively referred to as a first hole and a secondhole. Opposite ends of the liquid lens 3300 may protrude outward throughthe first and second holes formed in the opposite side surfaces of theholder 3500.

The holder may include a first hole formed in the surface thereof in thedirection perpendicular to the optical-axis direction. The liquid lensmay be inserted through the first hole such that at least a portion ofthe liquid lens is disposed in the first hole.

The holder may include a first side surface having a first hole and asecond side surface having a second hole facing the first hole. Thefirst lens unit and the second lens unit may be disposed in the holder.The liquid lens may be disposed between the first lens unit and thesecond lens unit, and at least a portion of the liquid lens may bedisposed in the first hole and/or the second hole. The liquid lens,disposed between the first lens unit and the second lens unit, mayprotrude outward from the side surfaces of the holder through the firsthole and the second hole. The thickness of the liquid lens may be lessthan the size of the first hole and/or the second hole in theoptical-axis direction.

The holder may include a second region, in which the liquid lens isdisposed, provided between the first hole and the second hole, and afirst region, in which the first lens unit is disposed, provided on thesecond region. In addition, the holder may include a third region, inwhich the second lens unit is disposed, provided under the secondregion.

The length of the liquid lens may be greater than the length of thefirst lens unit and/or the second lens unit in the direction from thefirst hole to the second hole.

The liquid lens may include a first plate including a cavity, in whichthe first liquid and the second liquid are disposed, a first electrodedisposed on the first plate, and a second electrode disposed under thefirst plate. In addition, the liquid lens may include a second platedisposed on the first electrode and a third plate disposed on the secondelectrode. The second plate and the third plate may be bonded to theholder using epoxy.

At least one of the second plate and the third plate may be spaced apartfrom at least one of the first region and the third region.

The first lens unit includes a plurality of lenses. The length of thelens of the first lens unit that is the closest to the liquid lens inthe direction perpendicular to the optical axis may be greater than thediameter of the portion of the cavity that is the closest to the firstregion. The second lens unit includes a plurality of lenses. The lengthof the lens of the second lens unit that is the closest to the liquidlens in the direction perpendicular to the optical axis may be greaterthan the diameter of the portion of the cavity that is the closest tothe third region.

In the first region, the inner wall of the holder may have a stair, andthe first lens unit may contact the stair. In the third region, theinner wall of the holder may have a stair, and the second lens unit maycontact the stair.

The first plate may include a through-hole formed through the firstplate. At least a portion of the upper electrode and at least a portionof the lower electrode may be connected to each other via a conductivedeposition layer disposed in the through-hole.

The cover 3600 may be disposed further outward so as to cover theprotruding portions of the liquid lens 3300. The cover 3600 may cover atleast a portion of the upper surface and the side surface of the holder,and may cover the first hole and the second hole.

The first and second holes may become the entrances of the liquid lens3300 when the liquid lens 3300 is inserted after the optical performanceof the first and second lens units 3100 and 3400 is evaluated in thestate in which the first lens unit 3100 and the second lens unit 3400are disposed in the holder 3500. In the lens assembly 3000 according tothe embodiment, the horizontal length d4 of the second region region2may be greater than the horizontal length d1 of the first region region1and the horizontal length d3 of the third region. In addition, thehorizontal length d2 of the second plate 3320 or the third plate 3330 ofthe liquid lens 3300 may be greater than the horizontal length d1 of thefirst region region1 and the horizontal length d3 of the third region.

The horizontal length d1 of the first region region1 may be thehorizontal length of the region of the first lens unit 3100 that isadjacent to the liquid lens 3300, and may be greater than the horizontallength c1 of the region of the cavity that is adjacent to the first lensunit 3100. The horizontal length d3 of the third region region3 may bethe horizontal length of the region of the second lens unit 3400 that isadjacent to the liquid lens 3300, and may be greater than the horizontallength c2 of the region of the cavity that is adjacent to the secondlens unit 3400.

In this structure, when the liquid lens 3300 is inserted into the secondregion region2, the second plate 3320 and the third plate 3330 of theliquid lens 3300 may protrude further laterally than the first regionregion1 and the third region region3, respectively. Consequently, theupper surface of the second plate 3320 and the lower surface of thethird plate 3330 of the liquid lens 3300 may be fixed in the state ofbeing in surface contact with the holder 3500.

The second plate 3320 and the third plate 3330 may be bonded to theholder 3500 using an adhesive such as epoxy. At least a portion of theliquid lens 3300 may be spaced apart from the inner surface of theholder 3500.

In addition, the region in which the upper surface of the second plate3320 of the liquid lens 3300 is in surface contact with the holder 3500and the upper surface 3310 a of the first plate 3310 may be disposedlower than the lower surface 3100 b of the first lens unit 3100. Theregion in which the upper surface of the second plate 3320 of the liquidlens 3300 is in surface contact with the holder 3500 or the uppersurface 3310 a of the first plate 3310 may be spaced apart from thelower surface of the first lens unit 3100 by the first gap gap1.

The region in which the lower surface of the third plate 3330 of theliquid lens 3300 is in surface contact with the holder 3500 and thelower surface 3310 b of the first plate 3310 may be disposed higher thanthe upper surface 3400 a of the second lens unit 3400. The region inwhich the lower surface of the third plate 3330 of the liquid lens 3300is in surface contact with the holder 3500 or the lower surface 3310 bof the first plate 3310 may be spaced apart from the upper surface ofthe second lens unit 3400 by the second gap gap2.

In FIGS. 33 and 34, the first and second connection electrodes 3356 and3346 may be connected to first and second contact electrodes 3357 and3347, and the first and second contact electrodes 3357 and 3347 may beconnected to the connection board 3380. Alternatively, the first andsecond connection electrodes 3356 and 3346 may be directly connected tothe connection board 3380.

The space between the holder 3500 and the cover 3600 may be filled witha second holder 3550. The holder 3500 and the second holder 3550 may bemade of the same material, and may be integrally formed.

The first lens unit 3100 may include two lenses 3110 and 3120. Theholder 3500 may have a stair structure at the inner wall of the firstregion region1, in which the first lens unit 3100 is received. The edgesof the lenses 3110 and 3120 may be fixed in the state of being insurface contact with the stair structure.

The second lens unit 3400 may include three lenses 3410, 3420, and 3430.The holder 3500 may have a stair structure at the inner wall of thethird region region3, in which the second lens unit 3400 is received.The edges of the lenses 3410, 3420, and 3430 may be fixed in the stateof being in surface contact with the stair structure.

In the camera module including the liquid lens according to theembodiment, the conductive liquid and the nonconductive liquid may bereceived in the cavity, and the conductive liquid and the nonconductiveliquid may not be mixed with each other so as to form the interfacetherebetween. The interface between the conductive liquid and thenonconductive liquid may be changed by the driving voltage applied tothe first and second electrodes 3355 and 3345 from the outside, wherebythe curvature and the focal distance of the liquid lens 3300 may bechanged.

As the curvature of the interface is controlled, the liquid lens 3300and the lens assembly 3000 and the imaging device including the same mayperform an optical zooming function, an auto focusing (AF) function, anda handshake compensation or optical image stabilization (OIS) function.In this case, the size of the camera module may be reduced. In addition,AF or OIS may be performed using electricity, whereby power consumptionmay be lower than in the case in which the lenses are mechanicallymoved.

The liquid lens is inserted into the holder. The upper and lowersurfaces of the liquid lens are in surface contact with the holder. Theliquid lens is spaced apart from the first and second lens by the firstand second gaps gap1 and gap2, respectively. Consequently, it ispossible to easily align the optical axes of the lenses in the cameramodule and to easily inhibit tilting of the lenses.

In the case in which the camera module is manufactured, the holder maybe configured such that the upper and lower portions of the holder areopen and such that the first hole and the second hole opposite to thefirst hole are formed in the side surface of the holder, the first lensunit may be coupled to the upper portion of the holder, the second lensunit may be coupled to the lower portion of the holder, and the liquidlens may be inserted through the first hole and/or the second hole. Atthis time, the liquid lens may protrude further outward than the sidesurface of the holder.

When the position of the liquid lens is adjusted in the state in whichthe side surface of the liquid lens, which protrudes further outwardthan the side surface of the holder, is supported, the position of theliquid lens may be adjusted to align the center of the liquid lens (e.g.the optical axis of the liquid lens or the center of the region in whichthe liquids are disposed) with the center of the first lens unit or thesecond lens unit (e.g. the center or the optical axis of the lens).

The position of the liquid lens may be moved in the plane perpendicularto the optical axis such that the center of the liquid lens is alignedwith the optical axis while the portions of the liquid lens protrudingoutward through the first and second holes formed in the side surface ofthe holder are held. Alternatively, the liquid lens may be rotated inthe plane perpendicular to the optical axis. Whether the optical axis ofthe liquid lens is tilted may be checked, and the tilting of the opticalaxis of the liquid lens may be adjusted such that the optical axis ofthe liquid lens is aligned with the optical axis of the lens assembly.

The liquid lens may be coupled to the holder using an adhesive such asepoxy. For example, the second plate and the third plate of the liquidlens may be bonded to the holder using epoxy. When the camera module ismanufactured, at least some of the above steps may be combined, or thesequence of the steps may be changed. For example, the liquid lens maybe disposed in the holder first, and then the first lens unit or thesecond lens unit may be disposed in the holder.

When tilting or other problems are observed after the opticalperformance of the first and second lens unit and the liquid lens isevaluated, the liquid lens may be replaced through one of the first holeand the second hole.

FIGS. 36A and 36B are perspective views from a first direction and asecond direction, respectively, of the holder of the camera module shownin FIG. 31.

Referring to FIG. 36A, the holder 3500 comprises a first side wallhaving a first hole, and, referring to FIG. 36B, the holder 3500comprises a second side wall having a second hole.

The camera module according to the embodiment may include all of thetechnical feature of the embodiment described with reference to FIGS. 1to 6 (first feature), the technical feature of the embodiment describedwith reference to FIGS. 9 to 14 (second feature), the technical featureof the embodiment described with reference to FIGS. 15 to 30 (thirdfeature), and the technical feature of the embodiment described withreference to FIGS. 31 to 35 (fourth feature).

For example, the camera module may include all of a feature in which theelectrode layer disposed on the upper surface of the first plate isconnected to the electrode layer disposed on the lower surface of thefirst plate via the through hole formed in the first plate (an exampleof the first feature), a feature in which the liquid lens is insertedthrough the insertion hole formed in the side surface of the holder (anexample of the second feature), a structure or manufacturing method forapplying voltage necessary to control the interface of the liquid lensusing the upper board and the lower board, which are integrally orindividually formed (an example of the third feature), and a feature inwhich the liquid lens is disposed so as to protrude outward from theside surface of the holder through the first hole and the second holeand the liquid lens is spaced apart from the inner surface of the holder((an example of the fourth feature).

In a camera module according to another embodiment, one or two of thefirst to fourth features may be omitted as needed.

In other words, the camera module according to the embodiment mayinclude any one of the first to fourth features, or may include acombination of at least two of the first to fourth features.

The camera module including the liquid lens may be mounted in variousdigital devices, such as a digital camera, a smartphone, a laptopcomputer, and a tablet PC. In particular, the camera module may bemounted in mobile devices to realize an ultra-thin high-performance zoomlens.

For example, a digital device or an optical device, configured such thatthe camera module, including the liquid lens, the first and second lensunits, the filter, and the light receiving element, converts an imageincident from the outside into an electrical signal, may include adisplay module including a plurality of pixels, the colors of which arechanged by the electrical signal. The display module and the cameramodule may be controlled by the controller.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and applications may be devised by those skilled inthe art that will fall within the intrinsic aspects of the embodiments.More particularly, various variations and modifications are possible inconcrete constituent elements of the embodiments. In addition, it is tobe understood that differences relevant to the variations andmodifications fall within the spirit and scope of the present disclosuredefined in the appended claims.

INDUSTRIAL APPLICABILITY

Embodiments relate to a lens, which is applicable to a camera moduleincluding a liquid lens and an optical device including the same.

1. A camera module, comprising: a holder comprising a side wall having ahole; a first lens unit comprising a plurality of lenses and fixed tothe holder; and a focus adjustable lens fixed in the holder, wherein thefocus adjustable lens overlaps the first lens unit in a first directionparallel to an optical axis direction.
 2. The camera module according toclaim 1, comprising: a second lens unit disposed in the holder, whereinthe focus adjustable lens is disposed between the first lens unit andthe second lens unit, and wherein a size of the hole is less than amaximum distance from the first lens unit to the second lens unit in thefirst direction.
 3. The camera module according to claim 2, wherein thefocus adjustable lens is spaced apart from at least one of the firstlens unit and the second lens unit.
 4. The camera module according toclaim 1, comprising a connection board disposed on the focus adjustablelens and a sensor board having an image sensor, wherein the connectionboard electrically connects the focus adjustable lens and the sensorboard through the hole.
 5. The camera module according to claim 4,comprising: a base disposed between the sensor board and the holder; anda cover covering at least a portion of the hole.
 6. The camera moduleaccording to claim 1, wherein the focus adjustable lens comprises afirst material and a second material different from the first material.7. The camera module according to claim 6, wherein the first materialcomprises water and the second material comprises oil.
 8. The cameramodule according to claim 1, wherein the hole comprises a first hole anda second hole, and wherein the second hole faces the first hole in asecond direction perpendicular to the optical axis direction.
 9. Thecamera module according to claim 8, wherein the focus adjustable lens isdisposed between the first hole and the second hole.
 10. The cameramodule according to claim 8, wherein the side wall comprises a firstside wall and a second side wall disposed opposite to the first sidewall, wherein the first side wall has the first hole, wherein the secondside wall has the second hole, and wherein the second hole penetratesthe second side wall.
 11. The camera module according to claim 9,wherein a part of the focus adjustable lens is disposed in at least oneof the first hole or the second hole.
 12. The camera module according toclaim 11, wherein a part of the focus adjustable lens protrudes outwardfrom the holder through at least one of the first hole or the secondhole.
 13. The camera module according to claim 11, wherein a length ofthe focus adjustable lens, measured in the first direction, is greaterthan a length of the first lens unit and greater than a length of thesecond lens unit, measured in the first direction.
 14. A camera module,comprising: a holder comprising a side wall having a hole; a first lensunit comprising a plurality of lenses and disposed in the holder; and afocus adjustable lens disposed on the first lens unit, wherein the focusadjustable lens overlaps the first lens unit in a first directionparallel to an optical axis direction, and wherein the focus adjustablelens is inserted through the hole and overlapped with the hole in asecond direction perpendicular to the optical axis direction.
 15. Thecamera module according to claim 14, comprising: a second lens unitdisposed in the holder, wherein the focus adjustable lens is disposedbetween the first lens unit and the second lens unit, wherein the sidewall comprises a first part overlapped with the first lens and the sidewall comprises a second part overlapped with the second lens in thesecond direction, and wherein the hole is formed between the first partand the second part.
 16. The camera module according to claim 14,wherein a part of the focus adjustable lens is disposed in the hole. 17.The camera module according to claim 16, wherein a size of the hole isgreater than a thickness of a center of the focus adjustable lens in thefirst direction and less than a length of the focus adjustable lens inthe second direction.
 18. The camera module according to claim 14,wherein the side wall comprises a first side wall and a second side walldisposed opposite to the first side wall, wherein the hole comprises afirst hole and a second hole, wherein the first side wall has the firsthole, and wherein the second side wall has the second hole.
 19. Thecamera module according to claim 17, wherein the first lens unitcomprises a plurality of lenses, and wherein the size of the hole issmaller than a length from a bottom surface of the plurality of lensesto a top surface of the plurality of lenses along the optical axis. 20.A camera module, comprising: a holder comprising a side wall having ahole; a first lens disposed in the holder; a second lens disposed in theholder; and an interface variable lens disposed between the first lensand the second lens, wherein the interface variable lens comprises afirst material, a second material on the first material, and aninterface between the first material and the second material, wherein apart of the interface variable lens is disposed in the hole, wherein asize of the hole is greater than a thickness of a center of theinterface variable lens, in a direction parallel to an optical axis, andwherein the size of the hole is less than a combined thickness, alongthe optical axis, of the interface variable lens and the first lens.